A. The problem that was reported to me was that when large files were copies from the server to any of the Mac-clients or from the Mac-clients to the server (about 10-15 MB). The server just crashed and the copying was not completed. If it was a folder with files inside, it just vanished, and nothing was left on the server.
The solution was to apply Service Pack 6a to the server which fixed the problem. The exact cause was unknown. It may have been a bad installation as others have reported no problems with only Service Pack 4/5 installed.
There is a known issue that an NT box, when it copies a large file, it tries
to cache it in memory before it pumps it out of its network card. If more than
one connection tries to copy the file, NT would eventually crash, because it ran
out of memory. Netware is unaffected by this.
Thanks to Paal-V. Hansen and Michael J.P. West