Hi,
I didn't had any issue, but today I installed the Horde fix. After it, I tried to access Horde webmail (atmail isn't installed) I got
'imp is not activated'
I fixed it with adding the Options from /etc/psa-webmail/horde/horde/registry.d/*.php files directly into /etc/psa-webmail/horde/horde/registry.php
This worked.
I also installed the Base-Packages Update (I think it's psa-hotfix3, but donno) with another problem, I will report in a new thread I think.