I have seen many posts about this problem and some seem to have been fixed
by a post 65sp2 patch or by modifying login scripts.

I have a freshly built NetWare 6.5 SP5 server where the home drive, which is
mapped by the %home_directory variable works but all other drive mappings
are empty. The script uses the map
f:=.servername_volume.ou=servers.o=org:\data syntax.

Also when I opened the NetStorage section in iManager v2.5.2 the first few
links worked then I got "Service not available. Possible cause:
Unauthorized" and there is a Java exception error in the logger screen and
now no NetStorage links in iManager work. I have seen this before (SP2, 3
and 4) but was hoping SP5 would fix some of these problems. I don't want to
have to re-boot the server (or reload apache-tomcat) every time I do some
admin on NetStorage.