Re: tag.php access issue
I would be interested to hear if you can use .htaccess, even though it’s unsupported. It’s also possible that they allow some things in .htaccess and not others. Maybe their solution is to rename all .php files to .php5 (not a good solution IMHO.)
A separate issue is if the switch from PHP4 to PHP5 is actually required or if it appears to fix the problem coincidentally.