Some Macintosh Server G4 (QuickSilver 2002) servers came with ten-user licenses instead of unlimited licenses.
Symptom
Only ten users can connect simultaneously to a Macintosh Server G4 (QuickSilver 2002) over SMB or AFP.
Solution
Some Macintosh Server G4 (QuickSilver 2002) servers came with incorrectly printed software serial numbers. The sticker on the Mac OS X Server CD sleeve indicates the software serial number is an unlimited license, but it is actually a 10-client license.
If you experience this symptom, you can have a replacement serial number issued to you at the Mac OS X Server Serial Number Exchange Web site (http://depot.info.apple.com/macosxserversn/)