Having strange issues with Macs and NFA.

We're using Novell Netware 6.5 SP5

Macintosh users are experiencing a problem with Netware when connecting
using Native FIle Access (AFP and SMB alike).

A Mac user can create a new file on the server, and the file will
simply not appear at all in the Finder. This eventually refreshes
itself (sometimes after minutes, sometimes after hours), and rebooting
the machine causes the file to appear.

Any suggestions?

Thanks in advance,
Sandon Jurowski