I think it would help if you give us more details about your browser version and any installed addons. Or download a plain vanilla portable browser and see if you can reproduce the issue.I'm not sure what's going, this is new for me... I log in and the moment I leave the login page, head to the forums or to post a comment on VLC at TPFC's main page I'm logged out... so I click login again and it starts all over. If there's a different login for posting comments on apps now, sorry, I didn't realize this.
All suggestions about TPFC should be posted here. Discussions about changes to TPFC will also be carried out here.