Kamal,
I had some classloading problems myself. I managed to solve them by putting the libraries either in the instance's lib/ext or the {glassfish_install}/lib as long as they don't conflict with existing glassfish libraries (the jsf.jar for example!).
As for the OutOfMemory error, you can always set the -XX:MaxPermSize=256m parameter (or even higher!) :
asadmin create-jvm-options \-XX\\:MaxPermSize=256m
you can also do it through the admin application.
Don't forget to restart the server after the command.
-Marios
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