spamassassin not working - debian 3.1

[fulltilt]

i have problems with spamassassin:

:~# cat /tmp/output.txt | grep fail
[2123] dbg: diag: module not installed: Net::Ident ('require' failed)
[2123] dbg: bayes: opportunistic call attempt failed, DB not readable
:~#

:~# /home/admispconfig/ispconfig/tools/spamassassin/usr/bin/sa-update --
error: gpg required but not found!

if i try to update with:
:~# /home/admispconfig/ispconfig/tools/spamassassin/usr/bin/sa-update --
error: gpg required but not found!

how can i fix spamassassin - running on debian 3.1 (postfix)
installed by:
The (Almost) Perfect Setup - Debian Sarge (3.1) On A Strato Dedicated-Server (With ISPConfig)

regards
Ralph