Hallo Ottmar,
hier ein Auszug aus einem Summary-Report der IBM:

PROBLEM SUMMARY:
After upgrading Windows 2000 to SP3 the following errors occur
when accessing files from an AS/400 NetServer share.

Microsoft Word documents opening as read-only. Microsoft Excel
files not opening with the error pop-up: "Microsoft Excel
cannot open or save any more documents because there is not
enough available memory or disk space" Installation of Client
Access Express from an AS/400 NetServer share failing with the
error pop-up: "Setup is unable to find installation languages
in X: ProdData CA400 Express Install Image SETUP.LID file.
Error 105" This problem is not limited to these errors and may
occur during other Windows 2000 SP3 accesses of an AS/400
NetServer share.

COMMENTS:
The problem introduced with the installation of the Windows 2000 SP3
is
fixed in v5r1m0.

CIRCUMVENTION:
Install PTFs MF26320 and MF26538 (MF26270 & MF26267 for V4R4),
then complete the following steps and try the operation again.

ENDTCPSVR *NETSVR

CALL QZLSADFS (QZLSMUX$ '/qibm' x'00000005' x'00000000'
'SA95732 - Windows 2000 SP3' x'00000002' x'ffffffff' x'00000000')

STRTCPSVR *NETSVR

Das hört sich doch nach Deinem Problem an - oder?
Gruss Reinhold