diff --git a/src/com/romraider/io/j2534/api/J2534ConnectionManager.java b/src/com/romraider/io/j2534/api/J2534ConnectionManager.java
index 3378d2a6..7cacdc0a 100644
--- a/src/com/romraider/io/j2534/api/J2534ConnectionManager.java
+++ b/src/com/romraider/io/j2534/api/J2534ConnectionManager.java
@@ -58,10 +58,10 @@ public final class J2534ConnectionManager implements ConnectionManager {
     }
 
     // Send request and wait specified time for response with unknown length
-    public byte[] send(byte[] bytes, long maxWait) {
-        checkNotNull(bytes, "bytes");
+    public byte[] send(byte[] request, long maxWait) {
+        checkNotNull(request, "request");
         // FIX - should maxWait be connectionProperties.getReadTimeout() ??
-        api.writeMsg(channelId, bytes, maxWait);
+        api.writeMsg(channelId, request, maxWait);
         return api.readMsg(channelId, maxWait);
     }
 
diff --git a/src/com/romraider/io/j2534/op20/Old_J2534OpenPort20.java b/src/com/romraider/io/j2534/op20/Old_J2534OpenPort20.java
index 9c8f383b..36b009e9 100644
--- a/src/com/romraider/io/j2534/op20/Old_J2534OpenPort20.java
+++ b/src/com/romraider/io/j2534/op20/Old_J2534OpenPort20.java
@@ -157,9 +157,9 @@ public final class Old_J2534OpenPort20 implements J2534 {
     }
 
     private boolean isResponse(PassThruMessage msg) {
+        if (msg.Timestamp == 0) return false;
         if (msg.RxStatus == 0x00) return true;
-        if (msg.RxStatus == 0x01) return true;
-        return msg.Timestamp != 0;
+        return msg.RxStatus == 0x01;
     }
 
     private PassThruMessage doReadMsg(int channelId) {