Mick F wrote:...
However, I've solved the problem.
It's all to do with the new forum address, but why, I don't know.
I had forum.ctc.org.uk as my bookmark, so when I opened up a new window and went to it, that's when I was logged out.
I've now deleted that bookmark and made another as forum.cyclinguk.org and it all now works as it should.
....
Weird because I'm still using the http://forum.ctc.org.uk/ and http://forum.ctc.org.uk/search.php?search_id=newposts as my bookmarks and am not having the same issues you were having (and my cookies setting is still set as yours is as I've not bothered to change it back after testing).
Ian