I have the exact problem listed in this TID:

Except that when I apply the fix that the TID suggest, it doesn't help.
I still have the same problem. A quick scan through the forum
doesn't show any help either.

It isn't really a problem except that my Helpdesk staff can't use
iManager to administer half the printers on my campus? So I guess
it is kind of a problem.

Many of these printers were migrated from a NW5.1 SP6 NDPS server to the
current NW6.5 SP2 NDPS. Actually the server was upgraded. If I delete
and recreate the PA then iManager works, but I don't really want to do
that for the 200 PA's? By "iManager works" i mean that I can browse
to the printer via iManager and access the panels for that printer.

NWAdmin still works, but iManager does not.

Here is my NLM info:
NDPSM.nlm 3.01.10, August 19, 2004
NDPSGW.nlm 3.01 May 5, 2004
BROKER.nlm 3.00.09, May 11, 2004
PH.nlm 3.00.02 May 27, 2004.

I did upgrade the NDPSGW.nlm to the one listed in the TID, but
decided to back rev it because I want my PAs to show up as
"Needs Attention" when the server can't ping it.
BTW, this brings up another question, what is the retry time for
the server to retry connecting to a Printer that it cannot Ping?

Brad Bendily