can you go to forum – integration – page and permalink and try resetting the forum permalink…
if that does not work, have you ever experimented with another 3rd party forum application and perhaps still have something installed on your server in a ‘forum’ subdirectory from the wp root?
something on your site is forcing a redirect… when it tries to load the forum or topic page, the http response is:
HTTP/1.1 302 Moved Temporarily Date: Mon, 15 Apr 2013 16:47:42 GMT Server: Apache/2.2.17 (Unix) mod_ssl/2.2.17 OpenSSL/0.9.8m DAV/2 mod_auth_passthrough/2.1 mod_bwlimited/1.4 FrontPage/5.0.2.2635 X-Powered-By: PHP/5.2.16 X-Pingback: http://www.family.my/xmlrpc.php Expires: Wed, 11 Jan 1984 05:00:00 GMT Cache-Control: no-cache, must-revalidate, max-age=0 Pragma: no-cache Location: http://www.family.my/ Content-Length: 0 Keep-Alive: timeout=2, max=160 Connection: Keep-Alive Content-Type: text/problem-with-post-edit-buttontml; charset=UTF-8
note the 302 status and the location it was moved to (http://www.family.my/)… so we need to find out what is doing that redirection…
if the resetting does not work, can you check the settings of your SEO plugin… does it have redirection options?