Update 3.1->3.3 Authentication cache failed

[webmaster zigann.de]

Hallo,

i have a running Kolab 3.1 on CentOS 6.5 and updated to version 3.3. The 
system works but is very slow and in calendar view not usable. I get in 
/etc/kolab/pykolab.log a lot of errors, i never had before:

2014-09-14 19:08:50,834 pykolab.auth ERROR Authentication cache failed: 
InvalidRequestError('The transaction is inactive due to a rollback in a 
subtransaction.  Issue rollback() to cancel the transaction.',)

Tried already a reinstall of roundcube

yum -y reinstall roundcubemail roundcubemail-plugins-kolab

but this didn't help.

Has anyone the same issue und how can it be fixed?

Regards

Torsten