NT client (3.1PTF3) problems with V2 server

Hi ADSM experts,
in our network we use a V2 ADSM server (MVS) and have NT clients using
V2.1PTF5.
As we want to upgrade to V3, we upgraded a few clients to V3 just to get
familiar with the software.
Now we have the following problem with the new clients:
The client looses its connection
  05/07/1998 01:41:40 ANS1114I Waiting for mount of offline media.
  05/07/1998 01:41:40 Retry # 1  Normal File-->        53,661,824
D:\HISTORY_MSG.DAT  ** Unsuccessful **
  05/07/1998 01:42:15 ANS1809E Session is lost; initializing session
reopen procedure.
The serverlog does not mention this error, so the session keeps alive
on server side.
The client does a little countdown, leading to
  A Reconnection attempt will be made in 00:00:00 ... successful
  05/07/1998 01:42:30 Retry # 2  Normal File-->        53,661,824
D:\HISTORY_MSG.DAT  ** Unsuccessful **
  05/07/1998 01:43:34 ANS1809E Session is lost; initializing session
reopen procedure.
This procedure gets repeated until all available serversessions are
occupied by this node
  A Reconnection attempt will be made in 00:00:00 ... failed
  05/07/1998 02:01:04 ANS1351E Session rejected: All server sessions are
currently in use

At this point the client window has elapsed and the backup gets
cancelled (status failed).
All created sessions are kept alive by the server for about 5.5 hours
and then cancelled all together (not as expected).

Has anybody occured this problem yet? Any solutions?

Thank you for any hints!
Regards,
Michael
--
Michael H. Bartl
Michael H. Bartl
ADAC e.V. (Rechenzentrum, Produktionsplanung und Organisation)
Tel.: (089) 7676-4063, Fax: (089) 7676-8161
EMail: Michael.Bartl AT Zentrale.ADAC DOT de