I had the same style problem on my page outside of the forum. Copying the clientscript and images folders in the directory the test.php page resides seemed to correct that.
The problem I can't figure out though... the links in the navbar and footer portion of the test page do not link properly if the page is outside of the forum folder. The address is missing the forum portion of the URL. Example: link leads to
http://www.yourdomain.com/register.php when it should lead to
http://www.yourdomain.com/forum/register.php.