Well just that really - by about an hour

This is a user-specific issue, please go to:
http://www.sheffieldforum.co.uk/profile.php?do=editoptions

Scroll about halfway down and ensure that you have the right time zone and also that you have DST correction enabled, automatic should be fine.

it's fine when I'm logged in, I just kind of expected it to be right for the time zone Sheffield is in when here as a 'guest' :thumbsup:

Don't mention the forum clock! :nono:

When you're not logged in the forum doesn't know whether you're in Sheffield or Timbuktu, so it's not surprising that it may be incorrect ;)