Yup.........

Here's what I did.

Logged off forums.
Cleared cookies from computer.
Restarted computer.
Logged on to forums.
Some threads highlighted as having new posts. So far so good.
Read all threads.
Closed browser
Opened browser
Forums marked with no new posts on front page.
Open any forum, all threads marked as having new posts.

I have pinned it down:

If I login, view the forums, then close the browser without logging off,reopen the browser and view the forums (login details saved in cookie), the problem happens. If I logoff, then when I reopen the browser and login, there's no problem.

However, doing this makes the Remember Me on the login page redundant.

It does the same in both IE and Firefox

excellent thanks for the debug info.

Rebles: sorry man i commented out a piece of code of your that takes care of what he just described, i'll enable it and see what happens.

Weird, it doesn't seem to happen anymore.

It looks like enabling the bit of code I had fixed the problem
(btw Tim, what was that bit of code?  *curious*)

i'll talk to you on msn rebles.

open up login.php and find the line containing:

fseek($v_file, (($_COOKIE["id_env"] - 1) * 14));

it should be around line 23, change this line to:

fseek($v_file, (($r["id"] - 1) * 14));