I am sometimes unable to connect to the forums on any of our pc-s or mobiles on any web browser application on any internet connection. My only tips are it's sth to do with my account or with the forum's servers.

Everything seems fine, I choose the PC as platform, I give the acc and pw, I tick the 'im not a robot" thing, which shows I am accepted, then I press login, it refreshes the forum site, and I am not logged in, it appears as i was logged out.

Then after a time (problem persists for some days) the problem magically disappears. I can log in again with the casual method. This is not the first time.

Also I would not write this if I didn't see other people being able to use the forum while I was not.

Net is fine. operating well.
Firewalls virus busters etc are fine, they do not block this page. I stated above the problem appears on different platforms and on different net connections.
I have no idea.