Errors after Upgrade from Plesk 7.5 to 8.0

Hello. We upgraded from SWSoft's Plesk 7.5 to Plesk 8.0 this morning. And we've had troubles ever since. We're running a dedicated Root server from [login to view URL] . Running Fedora Core 2. (Apache/2.0.51 (Fedora)) We have several Joomla installations that no longer work. Some safe mode errors. And our Horde webmail no longer seems to work (although qmail[?] still seems to work as our users can still access their mail through their clients). We need someone that can fix this quickly ! ! ! Please only bid if you are very experienced with this OS, Plesk, and Joomla.