Since this WAS actually caused by the IDM installation, I thought it
important to post this here as well.
After previously spending 4+ hours each time, on 2 different days, today
(the third time to talk to Novell tech support about this) a backend support
technician found the problem.
In reality, it DID have to do with installing the new version of Identity
Manger (maybe the older versions did this as well, I don't know).
Identity manager added the following line to my AUTOEXEC.NCF file:
# -- Required for DirXML Driver for GroupWise
SEARCH ADD SYS:\SYSTEM\GWDRIVER
It placed this high in the autoexec (right after the server name), which
means that sys:\system\gwdriver was the earliest additional search path.
There were four files in that directory: GWNL1US.FIL, GWENN5.NLM,
GWXIS12.NLM, and GWADJ12.NLM. Apparently, while all of the files are needed
by the identity manager (DirXML), the first three are loaded by GroupWise
(and updated) in other areas. This caused my GroupWise system to load the
incorrect version of GWENN5.NLM (and probably the other three as well),
which broke the system.
The solution was to either delete or move the other three files
(GWNL1US.FIL, GWENN5.NLM, GWXIS12.NLM), so the POA will load them from the