This is a multi environment issue, which seemingly needs at least 3
ingredients from Novell:
OES2SP2 running on SLES 10.2 64-bit fully patched
CIFS installed and running on that server
Novell Client 2 IR 2 or 3 for Windows 7
and maybe Novell Client 4.91 SP5 for Windows

If a user uses a file on the server from a Win7 box via the Novell
Client everything seems okay. Lateron somebody else uses this file
without problems from another box (eg WinXP) via NCP and has no
problems, too.
Now the problems start.
If someone else tries to open this file now (via NCP from XP or Win7 or
via CIFS) he can't open the file because it is in use.

If you use OES2SP2 on 32-bit SLES and SAMBA instead of CIFS no problems
If you do never open the file via Novell Client 2 from WIN 7 no problems

But this mixture is successfully locking files.
W. Prindl