That is core of the problem.
I didn't make any of manual changes.
I upgraded MySQL to 4.1, and installed webmin (but didn't changed anything using webmin), and added deleted few times /etc/postfix/virtusertable (below line for manual entries)
I had a lot of problems with ISPConfig please take a look at:
http://www.howtoforge.com/forums/sho...?t=2557&page=2