I had a
java path problem with a a new computer running xin/xp, j2se1.4
and j2ee1.3.1 that might be related to your problem or at any rate give you some food for thought.
As the computer came out of the box it had in the PATH a directory that had embedded spaces in it. Spaces in a directory name or a file name can confuse the java compiler and java runtime, in my experience.
What I did to fix it was to make sure the directory name that had embedded apaces was LAST in the "path". That way the java compiler and runtime found the java related directories prior to getting (harmlessly) confused by the non-java directories that have spaces.
This by the way is a problem that also happens if you install JDeveloper into the "Program Files" directory. The embedded spaces in "program files" cause problems.
So far I am: IBM 141 XML and Related Technologies Certified, Sun Cert Java Programmer, Sun Cert Java Developer, Sun Cert Java 2 Architect, Sun Cert J2EE Architect (part 1 only), Sun Cert J2EE Web Component Developer, Sun Cert Business Component Developer, and Microsoft Certified System Engineer for Win NT 4.