WordPress blank Permalink page / FTP credential

I moved my WP from a shared server to VPS.net. Here I have CentOS 5.4 x64 with cPanel and WHM, with LiteSpeed Enterprise license.

But I have these problems: when I try to install / delete a plugin via WordPress, come out a page with FTP credential request.
Also, some plugins (I think they are the ones that have many KB) takes too long to install (or delete), so that the page seems stuck. So, after some minutes with no confirmed message, if I go back in the Plugins Page I see my plugin installed or removed.

In addition ([B]and this is my biggest problem[/B]) I can not access the page Permalinks. The link is there, but the page is blank.

I thought it might be a problem with my old configuration WP. But now I have created a clean install of WordPress via SSH on a different domain and I have the same problems (with no plugins enabled).

If anyone wants to see my phpinfo configuration, you can do from here: http://www.ofertebebe.ro/phpinfo.php

Nick Nelson, from VPS.net, he configured my server so I assume that everything is ok. Indeed, he told me he saw a similar situation with another client with LiteSpeed server. So, indirectly, he advised me to ask in the LiteSpeed forum.

I have a oppened discussion on the VPS.net forum, http://www.vps.net/forum/public-forums/the-lounge/2248-server-changed-wp-install-plugin-ftp-credential and here http://www.vps.net/forum/public-forums/the-lounge/2247-change-server-blank-wordpress-permalink-page (I do not know if it is accessible to unregistered users).
Also, in the LiteSpeed forum http://www.litespeedtech.com/support/forum/showthread.php?t=3971

Some idea?