My hosting service upgraded my site from PHP4 to PHP5, and changed some of the directory structure. I modified the XOOPS_ROOT_PATH value in mainfile.php without problem, but I'm getting several errors when trying to display the site; the first error is

Unknown Condition [2048]: Non-static method XoopsLogger::instance() should not be called statically in file include/common.php line 59

I have been unable to pinpoint the problem here. Any hints, advice, etc would be appreciated.