[exim] Problem to set gid or uid

Hi, all!

Since some days we have, on just one Server of the cluster (all Server have the
same Version [4.51] of Exim and the same configuration!), these errors:

2005-12-20 10:26:30 unable to set gid=101 or uid=501 (euid=501): virtual_forward router (recipient is j.hauck@???)
2005-12-20 10:26:30 internal problem in virtual_forward router (recipient is j.hauck@???): failure to transfer data from subprocess: status=0100 readerror='Operation now in progress'
2005-12-20 10:26:30 H=(mailin03.ims-firmen.de) [192.168.1.112] sender verify defer for <j.hauck@???>: internal problem in virtual_forward router (recipient is j.hauck@???): failure to transfer data from subprocess: status=0100 readerror='Operation now in progress'
2005-12-20 10:26:30 H=(mailin03.ims-firmen.de) [192.168.1.112] F=<j.hauck@???> temporarily rejected RCPT <j.hauck@???>: Could not complete sender verify
2005-12-20 10:26:30 unexpected disconnection while reading SMTP command from (mailin03.ims-firmen.de) [192.168.1.112]

The Servers save the E-Mail on a remote disk (on a NetApp FAS270, using NFS).
4 Server have no problem, just the fifth has since some days, this problem.
I didn't change the configuration in these period, and I don't have any idea
what the problem is...

Can someone help me to understand what and where the problem is?

Thanks a lot!
--
_______________________________
Luca Bertoncello
-Programmierung / Mailserver-

IMS Internet-Media-Service GmbH
Bärensteiner Straße 7
01277 Dresden

Fon: +49 351 2112034
Fax: +49 351 2112020
email: bertoncello@???