win7 application hang with novell client

I'm using my own application developed with ACUCobol. This application run on windows XP machines and OES server. Even is working on Win7 on pure windows environment (no OES). On a new win7 machine 64 bits (OES server), Novell Client 2 SP2 per Windows 7 (IR5), I have problems when others users access the same applications. This seems related to lock files, so I've disenabled lock file (file cache off on novell client's properties). This was done even on XP machines. The XP machines works fine, but win7 hang. I've read some post, on Novell's forum, and other, I've tryed a lot of test without success. Anyone have some suggestions,
Thanks,
Fabrizio