[OpenAFS] Cache Manager drops tickets

[Kai Moritz]

Hi folks!

I set up an openafs fileserver to replace our old nfs system. Everything
is running fine, but i have some strange problems while copying the old
user data to the new system:
I cannot install an openafs-client on the machine, where the old data is
  living on (called zimt). So I simply logged into a machine with
openafs-client (called brunhild) as root and got tickets for my
afs-adminuser via "kinit afsadmin" and "aklog". Then I start an rsync on
zimt like this "rsync -av /home root@brunhild:/afs/cellname/user". All
works fine in the beginning, but after some time (5-30 min) the rsync
command is interrupted because of access-problems. Issuing "tokens" on
brunhild shows, that the cache manager has dropped the token, althoug it
was not expired.
I cannot figure out why... There are no error-messages in the
openafs-log-files. Time is synchronized and another aklog fetches a new
token without any problems.

I am running openafs 1.4.1 with MIT Kerberos on a Debian Sarge system.

Greetings Kai Moritz