Use IBM FixPack1 for WebSphere 5.1 installations
Symptom
For certain platforms, a bug in IBM WebSphere 5.1 may prevent Process Commander from running. This problem appears when a user first logs on and tries to display a portal.
Tracebacks on this issue report that the same object is being released into the StringBufferFactory multiple times.
Explanation
The issue occurs because of a bug in IBM's Java 1.4.1 just-in-time (JIT) compiler. This error is known to occur on Windows systems, and may also occur on AIX, Linux, and z/OS systems, which share similar IBM JIT technology. It should not be an issue on Solaris, as WebSphere uses an IBM-modified version of Sun's JVM for that platform.
Disabling the JIT allows Process Commander to run correctly, but the performance is so slow as to be unusable.
Solution
Resolution
Applying WebSphere 5.1 fix pack 1 (also known as WebSphere 5.1.1) upgrades the IBM JVM version to 1.4.2 (cn1420-20040626 on Windows). This JVM fixes the problem, and allows Process Commander to run correctly under WebSphere.
This fixpack is available at http://www-1.ibm.com/support/docview.wss?rs=180&uid=swg24007195