When working with any of IBM products like Websphere, Thread Dump Analyzer developed by IBM or those n number of other Java tools, if you run into issues despite getting all obvious things correct one worthy check would be to see if the tool works with the JVMs other than the one developed by IBM.

Because most of the cool and awesome Java tools created by IBM are not compatible with JVMs other than the one developed by it.

This assumption usually wastes lot of time causing frustration.