PHP5 is out and if your ISP change to php5 you may run in trouble with threads. Nothing work from scratch anymore.
The workaround must be done in ubb.inc.php (in all threads versions). For 6.4.3 do a global replacement of $this to $thisUBB. Problem: some $this must be leaved as is. After the global replacement you notice errors while try to login/logout. change these back (line numbers will be show by error message). After changing this back you can login and continue testing.
If you try out 6.5 go to line 1707 and replace from here all $this to $thisUBB up to the end of the file. Done.
Other problems exists in several hacks. PPpanel need a little modification for the next button (description in the thread), LinksDB need lastest file modifications to work again (lots of modification), Photopost IIP pal box need modification and maybe several other hacks.
The problem is changing the default handling of global variables. This can be also modified with changing the .htaccess (if you have access to it). Put this in the file: php_flag register_globals on
This fix the problem for scripts in the same directory, but maybe open a little security hole again.
I hope this help a little bit if you run i trouble like me
