I turned errors on and got the following.
when trying to go to
http://www.solo2.org/ubb/ultimatebb.php PHP Notice: Undefined index: QUERY_STRING in e:siteschrissolo2-orgubbultimatebb.php on line 852
and when trying to go to
http://www.solo2.org/ubb/ultimatebb.php?ubb=forum;f=12
PHP Notice: Undefined index: HTTP_REFERER in e:siteschrissolo2-orgubbultimatebb.php on line 847 PHP Notice: Undefined index: HTTP_REFERER in e:siteschrissolo2-orgubbultimatebb.php on line 852
haven't lookged into the code for that yet.