[horde] Error retrieving session data

[Bas Benschop]

Good evening,

I suddenly have a login problem with my horde/imp configuration.
It worked fine for a few weeks but suddenly nobody can login anymore.
Autentication is done via IMP with a IMAP server.
The horde log states:

Apr 06 22:34:17 HORDE [notice] [imp] Login success for bas [145.99.205.245]
to {kwark.tnw.utwente.nl:143} [on line 152 of
"/usr/share/horde3/imp/redirect.php"]
Apr 06 22:35:09 HORDE [error] [horde] Error retrieving session data (id =
15b68126e80b6a7e0b3e358977830bfd) [on line 110 of
"/usr/share/horde3/lib/Horde/SessionHandler/mysql.php"]
Apr 06 22:36:00 HORDE [error] [horde] Error writing session data [on line
144 of "/usr/share/horde3/lib/Horde/SessionHandler/mysql.php"]
Apr 06 22:36:51 HORDE [error] [horde] Error retrieving session data (id =
15b68126e80b6a7e0b3e358977830bfd) [on line 110 of
"/usr/share/horde3/lib/Horde/SessionHandler/mysql.php"]

The strange thing is that after about 2 minutes the left pane shows my info,
new mails etc, but the login screen gets back. Everyting I select in the
left pane
brings back the login screen.

I use a debian etch system running apache 2.2.3, PHP 5.2, mySQL 5.0.32,
horde 3.1.3 and imp 4.1.3.

Somebody any clue?

Regards,
Bas Benschop
University of Twente