yes its Plesk 10.1.1
running on Centos 5.5
Parallels Plesk Reloaded(TM) Power Pack
Plesk Hosting Suite 10.1.1
Plesk Panel Unlimited Domains,
Sitebuilder 100 Sites,
Plesk Billing 1000 Accounts
we updatet from 10.0.1 to 10.1.1 in two steps ;-)
problem startede in 10.1.0 and stayed...