visual vm unable to connect to jvm

http://docs.oracle.com/javase/6/docs/technotes/guides/visualvm/index.html

I can see the java processes running, but I can't connect to them by runnning jvisualvm on the same box as the java process.

So I try:
./jinfo 10248
Attaching to process ID 10248, please wait...
Error attaching to process: sun.jvm.hotspot.debugger.DebuggerException: Can't attach to the process

All of a sudden I realize that I was logged in with a different Unix login as the Java process.... logging in with the same Unix user and then running jvisualvm fixed the problem.