Thanks for your replay!
Ouch, alright. Anyway... don't worry about it anymore. After a day of not answearing OVH support I decided to reinstall the server.
But now I've other problem. So... I added DNS config for my domain, for my subdomains etc. Then in tab 'Sites' added these domains/subdomains and I though that everything works perfectly. I was able to see the welcome script. Then I copied backup of my sites. (client1 folder). Gave to it premissions, and the WordPress script was working. But IPBoard wasn't. I though that's a problem with DNS or something, so I decided wait a sec. I've just changed (on my local PC) from Windows to Ubuntu, and after that when I was trying to check if my IPBoard script is working now - it did! Yey! I was happy as a f... you know what I mean. :P But then I was trying to access to my WordPress script. And what? I see the welcome index.html file. Sure I've changed the rediect settings. Even was trying to do other thing. I've changed the index.html file? And you know what happend? NOTHING! It just looks like it wasnt in that folder.
About my configuration? Well, I'm using Debian 6 Squeeze + ISPConfig 188.8.131.52(?). That's all I know about configuration, everything is same like I'd get it all from OVH installation. Didn't change anything.