Mount point already in use - when adding subdomains

[2xmy]

I don't understand, that it should not be possible to point several subdomains to the same mount point. I already do this with domain alias'es without problems.

I use the following version
ispCP 1.0.0 OMEGA
build: 20090225

I get the error, when I add a subdomain and choose "/" as my "Directory tree mount point".

I can see that others have had the same problem, but they did not receive an solution:
http://www.isp-control.net/forum/thread-7079.html

Btw: If any of you are good at ispCP and offer paid help with ispCP, then please send me a PM.