This may be because your GF V2 is installed using 1.5.0_07 and and your EJB module must be built with a higher version maybe JDK 6?
FYI You can change the jdk which is GF is using by modifying AS_JAVA variable in
$installdir/config/asenv.conf(bat for win)
Regards,
Bhakti
[Message sent by forum member 'bhaktimehta' (bhaktimehta)]
http://forums.java.net/jive/thread.jspa?messageID=209526