diff --git a/js/controllers/setup.js b/js/controllers/setup.js
index 4f8030434..6020b4acb 100644
--- a/js/controllers/setup.js
+++ b/js/controllers/setup.js
@@ -1,5 +1,37 @@
 'use strict';
 
+
+var valid_pairs = {
+  '1,1': 112,
+  '1,2': 147,
+  '2,2': 220,
+  '1,3': 182,
+  '2,3': 256,
+  '3,3': 329,
+  '1,4': 216,
+  '2,4': 290,
+  '3,4': 363,
+  '4,4': 436,
+  '1,5': 250,
+  '2,5': 324,
+  '3,5': 398,
+  '4,5': 470,
+  '1,6': 284,
+  '2,6': 358,
+  '3,6': 432,
+  '1,7': 318,
+  '2,7': 392,
+  '3,7': 465,
+  '1,8': 353,
+  '2,8': 427,
+  '1,9': 387,
+  '2,9': 461,
+  '1,10': 421,
+  '2,10': 495,
+  '1,11': 455,
+  '1,12': 489
+};
+
 angular.module('copay.setup').controller('SetupController',
   function($scope, $rootScope, $location, $timeout, walletFactory, controllerUtils, Passphrase) {
 
@@ -9,7 +41,7 @@ angular.module('copay.setup').controller('SetupController',
 
     // ng-repeat defined number of times instead of repeating over array?
     $scope.getNumber = function(num) {
-      return new Array(num);   
+      return new Array(num);
     }
 
     $scope.totalCopayers = config.wallet.totalCopayers;
@@ -18,10 +50,11 @@ angular.module('copay.setup').controller('SetupController',
       $scope.TCValues.push(n);
 
     var updateRCSelect = function(n) {
-      $scope.requiredCopayers = parseInt(Math.min(n / 2 + 1, config.limits.mPlusN-n));
+      $scope.requiredCopayers = (valid_pairs[[parseInt(n / 2 + 1), n]] > 0 || config.networkName === 'testnet') ?
+          parseInt(n / 2 + 1) : 1;
       $scope.RCValues = [];
       for (var m = 1; m <= n; m++) {
-        if (n + m <= config.limits.mPlusN) {
+        if (valid_pairs[[m, n]] > 0 || config.networkName === 'testnet') {
           $scope.RCValues.push(m);
         }
       }
@@ -35,15 +68,18 @@ angular.module('copay.setup').controller('SetupController',
 
     $scope.create = function(form) {
       if (form && form.$invalid) {
-        $rootScope.$flashMessage = { message: 'Please, enter required fields', type: 'error'};
+        $rootScope.$flashMessage = {
+          message: 'Please, enter required fields',
+          type: 'error'
+        };
         return;
       }
       $scope.loading = true;
-      Passphrase.getBase64Async($scope.walletPassword, function(passphrase){
+      Passphrase.getBase64Async($scope.walletPassword, function(passphrase) {
         var opts = {
           requiredCopayers: $scope.requiredCopayers,
           totalCopayers: $scope.totalCopayers,
-          name: $scope.walletName, 
+          name: $scope.walletName,
           nickname: $scope.myNickname,
           passphrase: passphrase,
         };
diff --git a/js/models/core/Wallet.js b/js/models/core/Wallet.js
index f221378ad..9bba3a6c0 100644
--- a/js/models/core/Wallet.js
+++ b/js/models/core/Wallet.js
@@ -426,7 +426,10 @@ Wallet.prototype.sign = function(ntxid, cb) {
   setTimeout(function() {
     var myId = self.getMyCopayerId();
     var txp = self.txProposals.txps[ntxid];
-    if (!txp || txp.rejectedBy[myId] || txp.signedBy[myId]) return;
+    if (!txp || txp.rejectedBy[myId] || txp.signedBy[myId]) {
+      if (cb) cb(false);
+      return;
+    }
 
     var pkr = self.publicKeyRing;
     var keys = self.privateKey.getAll(pkr.addressIndex, pkr.changeAddressIndex);
@@ -455,6 +458,10 @@ Wallet.prototype.sendTx = function(ntxid, cb) {
   if (!tx.isComplete()) return;
   this.log('[Wallet.js.231] BROADCASTING TX!!!'); //TODO
 
+  var scriptSig = tx.ins[0].getScript();
+  var size = scriptSig.serialize().length;
+  alert('\t scriptSig size: '+size);
+
   var txHex = tx.serialize().toString('hex');
   this.log('[Wallet.js.261:txHex:]', txHex); //TODO
 
diff --git a/test/find_m_n.js b/test/find_m_n.js
deleted file mode 100755
index 4ea1c7518..000000000
--- a/test/find_m_n.js
+++ /dev/null
@@ -1,90 +0,0 @@
-#!/usr/bin/env node
-
-'use strict';
-
-var async = require('async');
-var bitcore = require('bitcore');
-var PublicKeyRing = require('../js/models/core/PublicKeyRing');
-var PrivateKey = require('../js/models/core/PrivateKey');
-
-var FakeNetwork = require('./mocks/FakeNetwork');
-var Insight = require('../js/models/blockchain/Insight');
-var FakeStorage = require('./mocks/FakeStorage');
-
-var WalletFactory = require('soop').load('../js/models/core/WalletFactory', {
-  Network: FakeNetwork,
-  Blockchain: Insight,
-  Storage: FakeStorage,
-});
-var Key = bitcore.Key;
-
-
-var N_LIMIT = 20;
-var nn = 'livenet';
-
-for (var n = 1; n <= N_LIMIT; n++) {
-  var end = false;
-  for (var m = 1; m <= n; m++) {
-    // case m-of-n
-    console.log('case ' + m + '-of-' + n);
-    // create full pkr
-    var publicKeyRing = new PublicKeyRing({
-      networkName: nn,
-      requiredCopayers: m,
-      totalCopayers: n,
-    });
-    var privateKey = null;
-    var pks = [];
-    for (var i = 0; i < n; i++) {
-      var pk = new PrivateKey({
-        networkName: nn
-      });
-      if (i === 0) {
-        privateKey = pk;
-      } else {
-        publicKeyRing.addCopayer(pk.getExtendedPublicKeyString(), 'dummy');
-      }
-      pks.push(pk);
-    }
-
-    var opts = {};
-    opts.publicKeyRing = publicKeyRing;
-    opts.privateKey = privateKey;
-    opts.requiredCopayers = m;
-    opts.totalCopayers = n;
-    opts.spendUnconfirmed = true;
-    opts.version = 'script'
-
-    var w = new WalletFactory(opts).create(opts);
-    var addr = w.generateAddress();
-    console.log('\t receive addr=' + addr);
-
-
-    var toAddress = 'msj42CCGruhRsFrGATiUuh25dtxYtnpbTx';
-    var amount = '5000000';
-    // create fake utxo
-    var utxos = [{
-      'address': addr,
-      'txid': '82a974b72d3135152043989652e687e2966c651ba4822274926221017ea072d2',
-      'vout': 1,
-      'ts': 1400696213,
-      'scriptPubKey': 'a914b2562c950498ff48ad3479ca1c2dfda2b0273e2287',
-      'amount': 10.0,
-      'confirmations': 2
-    }];
-    var ntxid = w.createTxSync(toAddress, amount, utxos);
-    console.log('\t ntxid =' + ntxid);
-    var txp = w.txProposals.txps[ntxid];
-    var tx = txp.builder.build();
-    var scriptSig = tx.ins[0].getScript();
-    var size = scriptSig.serialize().length;
-    console.log('\t scriptSig size: '+size);
-    if (size > 500) {
-      if (m === 1) {
-        end = true;
-      }
-      break;
-    }
-  }
-  if (end) break;
-}
diff --git a/util/find_m_n.js b/util/find_m_n.js
new file mode 100755
index 000000000..88364fe6d
--- /dev/null
+++ b/util/find_m_n.js
@@ -0,0 +1,123 @@
+#!/usr/bin/env node
+
+'use strict';
+
+var async = require('async');
+var bitcore = require('bitcore');
+var chai = require('chai');
+var should = chai.should();
+var PublicKeyRing = require('../js/models/core/PublicKeyRing');
+var PrivateKey = require('../js/models/core/PrivateKey');
+
+var FakeNetwork = require('../test/mocks/FakeNetwork');
+var Insight = require('../js/models/blockchain/Insight');
+var FakeStorage = require('../test/mocks/FakeStorage');
+
+var WalletFactory = require('soop').load('../js/models/core/WalletFactory', {
+  Network: FakeNetwork,
+  Blockchain: Insight,
+  Storage: FakeStorage,
+});
+var Key = bitcore.Key;
+
+
+var N_LIMIT = 50;
+var ITERS = 5;
+var nn = 'livenet';
+
+var maxs = {};
+var valid = {};
+
+for (var n = 1; n <= N_LIMIT; n++) {
+  var end = false;
+  for (var m = 1; m <= n; m++) {
+    // case m-of-n
+    console.log('case ' + m + '-of-' + n);
+    var pair = [m, n];
+    for (var iter = 0; iter <= ITERS*n; iter++) {
+      // create full pkr
+      var publicKeyRing = new PublicKeyRing({
+        networkName: nn,
+        requiredCopayers: m,
+        totalCopayers: n,
+      });
+      var privateKey = null;
+      var others_pks = [];
+      for (var i = 0; i < n; i++) {
+        var pk = new PrivateKey({
+          networkName: nn
+        });
+        if (i === 0) {
+          privateKey = pk;
+        } else {
+          publicKeyRing.addCopayer(pk.getExtendedPublicKeyString(), 'dummy');
+          others_pks.push(pk);
+        }
+      }
+
+      others_pks.length.should.equal(n - 1);
+
+      var opts = {};
+      opts.publicKeyRing = publicKeyRing;
+      opts.privateKey = privateKey;
+      opts.requiredCopayers = m;
+      opts.totalCopayers = n;
+      opts.spendUnconfirmed = true;
+      opts.version = 'script'
+
+      var w = new WalletFactory(opts).create(opts);
+      var addr = w.generateAddress();
+
+      var toAddress = 'msj42CCGruhRsFrGATiUuh25dtxYtnpbTx';
+      var amount = '5000000';
+      // create fake utxo
+      var utxos = [{
+        'address': addr,
+        'txid': '82a974b72d3135152043989652e687e2966c651ba4822274926221017ea072d2',
+        'vout': 1,
+        'ts': 1400696213,
+        'scriptPubKey': 'a914b2562c950498ff48ad3479ca1c2dfda2b0273e2287',
+        'amount': 10.0,
+        'confirmations': 2
+      }];
+      var ntxid = w.createTxSync(toAddress, amount, utxos);
+      var txp = w.txProposals.txps[ntxid];
+
+      var signTx = function(pk, cb) {
+        var pkr = publicKeyRing;
+        var keys = pk.getAll(pkr.addressIndex, pkr.changeAddressIndex);
+
+        var b = txp.builder;
+        var before = b.signaturesAdded;
+        b.sign(keys);
+
+        return cb();
+      }
+
+      async.eachSeries(others_pks, signTx, function(err) {
+        if (err) {
+          throw err;
+        } else {
+          var tx = txp.builder.build();
+          var scriptSig = tx.ins[0].getScript();
+          var size = scriptSig.serialize().length;
+
+          maxs[pair] = Math.max(maxs[pair] || 0, size)
+        }
+      });
+
+    }
+    var size = maxs[pair];
+    console.log('\tmax size: '+size);
+    var m_valid = false;
+    if (size < 500) {
+      m_valid = true;
+      valid[[m,n]] = size;
+    }
+    if (!m_valid) break;
+  }
+  if (!m_valid && m === 1) break;
+}
+
+
+console.log(valid);