I've the same symptoms since yesterday.
I've updated from jdk 1.5.0_06 to 1.5.0_12 and Eclipse 3.3 with wtp 2.0.
I deinstalled 1.5.0_06 first.
Since that the deployed jsp files are not able to get my hibernate-packages.
I tested it with parallel installations of jdk 1.5.0_10 and 1.5.0_06.
I builded and deployed my sources and started the JBoss several times with completely different JDK but I've still this problem.
I also get my old backup of eclipse-workspace and switched completely backwards to 3.2. No change.
I started the JBoss through eclipse debug mode and from the console with run.bat.
Now I'm going to reinstall a backup of my jboss-directory. Mayby there is a wrong configuration.
Not sure what the issue is. See if this works - delete the contents of the %JBOSS_HOME%/server//work folder and restart JBoss.
Not sure what the issue is. See if this works - delete the contents of the %JBOSS_HOME%/server/<< theServerYouAreUsing>>/work folder and restart JBoss.
First of all: on windows you have to restart the system after changing the environment variables (like JAVA_HOME, CLASSPATH,...). ;-)
To ensure having a clean new build I deleted /work and /tmp of JBoss-server.
After each reboot I rebuild and redeployed the whole project.
So far I can say: _06 is working. _10 and _12 don't.
I didn't test more jdk-versions.
So be aware of the risks of changing jdk-versions without any tangible need.
Never change a running system.