The Read Me for the AppleShare Client 3.7 states that the NetWare User Authentication Module is incompatible with AppleShare Client 3.7, and to contact Novell for an update.
You can obtain a newer, not fully tested version of the NetWare UAM from Novell at the following ftp site:
ftp://ftp.novell.com/pub/netwire/nsd/mclupd2.bin.
It appears to work properly with the AppleShare Client 3.7, but has not been fully tested by Apple Computer, Inc.