Currently I'm confronting with Reverse IP problem because I have several (sub)domains on the same IP.
The problem was described at: http://www.howtoforge.com/forums/showthread.php?t=57508
I'll not write all things that I wrote there because are explained at that link.
My request is:
1. In ISPConfig set a default domain for an IP
2. Let us to change name of virtual host file to put it as the default