I don't know if this could be my computer but for the last couple of days whenever I visit the forums every one has a tick next to it showing a new comment has been added. But when I open the forum many times there are no new additions. I recently used Disc Cleanup to clear some space on my hard drive [including temporary internet files], and reset the calendar to a month earlier to avoid losing a trial photo software that was due to expire. could it be this causing the problem? I'm a total no brainer on computers.

I believe that that information stored in a cookie on your machine. So the clean up got rid of it. Potentialy, with the caching of pages you may not be refreshing the 'check box'.
Try this - go into a forum that has new threads click F5 to refresh the page. Then use the Forum menu, not the back key to go back and try another forum.
This will force the creation of the cookie and may solve the problem.

That's just a theory - Jim would know much better.

Thanks Scott, I gave it a try but no luck, still showing new posts in every forum.

Hmm....Try hitting CTRL + F5 instead.

Jim

Actually I just deleted all my cookies and cache info and when you visit the forum for the first time there are no topics showing as new. This makes sense really because the system has no idea when you last visited the site. So...based on that I would say you probably have a corrupted cookie that is feeding the wrong date to the forum and giving it the impression that all topics are dated newer than your last visit date. Just a guess.

I guess we need a "Mark all topics as read" button.

Jim

Thanks Jim, I tried ctrl+F5 and no joy, I tried cleanup again, no joy, tried ctrl+F5 and everything is back to normal. Problem solved