Hope someone can help me with this strange problem. I have recently signed on to a web forum (for BMW motorcycles

) but I cannot stay logged in. I open the site, and either I am already logged in or I manually log in. This takes me to the index page but when I try to navigate to any other page, I am automatically logged out
I have tried deleting my cookies and starting again but this does not seem to make any difference. I assumed it was a problem with their server but when I access the site from my office PC - no problems! I have emailed the site support (no response yet) but I am now thinking it must be something to do with my PC.
Privacy settings on IE are set to "Accept all cookies"; I have ZoneAlarm Pro running and Session, Persistent and Third Party cookies are allowed for this site.
Any ideas, anyone?
Aiglon