5
I also had a similar problem where some hackers managed to insert links to crack sites into custom blocks I had made on my index.php thus messing up the front page and messing up admin.php.
The solution to fix this was to simply delete all files within /cache and templates_c, I can only surmise that they managed to somehow alter the cached files within these directories, after all they have to be world writable/readable(chmod 777) to function properly I t beleive.
I'm still not sure if it is a direct problem with XOOPS or if my server was at fault.
Michael Jackson = King Of Pop
Xoops = King Of CMS