Oh mighty aggregated ADSM knowledge !

Today I encountered the following:

I start an incremental backup via server scheduler on the home server of
our NT Network (details below). It should back up the System Partition (C:
1 GB) and the data partition (D: 15GB). The system partition is no problem
but the data partition is. After about 100.000 files and 40 to 50 minutes
of working I get an "ANS4031S Internal program error.  Please see your
service representative." error without anything else. The process
terminates with a return code of 131. After looking into some old log files
I found out that this error is happening for at least the last week (I have
no older log files); there is no unusual entry in the actlog of the server
at this time. Is there anyone out there with an idea what that might be?

Involved Systems:
Client:
IBM PC Server 330
IBM ServerRaid System
Windows NT 4 Server (SP3)
ADSM Client 2.1.0.6

Server:
IBM RS/6000 modell 250
AIX 4.1.4
ADSM 2.1.5.15

Thanks, Steffen