The URL you posted didnt' work (server not found) until I took the "www" out. Make sure you're not using that anywhere else, or people will get errors.
When I took the www out, I saw your errors. It sure looks to me that the $thispath variable is set incorrectly.
What Path do you have in your main.inc.php file for $thispath?
From the errors, I'm thinking that you should have something like:
/home/virtual/site5/fst/var/www/html/ubbthreads
