Problem with lastvisit time for some users

[sv1cec]

Folks,

I am facing a small problem lately, which seems to affect a couple of my users, however one of them being my assistand Admin, I have to figure out how to solve it.

The problem is that for these particular users, the lastvisit time seems to change at the wrong moment. For example:

When I go to my site, I usually check my PMs, answer them etc. Then I usually do a "Search for new posts since your last visit", which brings up all the new posts. If I make sure that I do not reach the cookie time-out limit, then my lastvisit time does not change. If that particular other admin does the same, his lastvisit time changes, as soon as he goes check his PMs.

I have tried to find out when the lastvisit time should be changed by vB and it looks as if it is done either when you log off, or when your session expires due to the cookie timeout.

Since this does not happen to me (and to almost no other user, as far as I can tell), I can't duplicate the problem and I tend to believe it is an end-user problem related to the specific environment of my co-admin.

Has anyone ever seen this problem before?

Details:

Running latest version of vB 3.0.xx, heavily patched.
User was running Windoze 98, lately upgraded to WinXP without any difference in the behaviour.
User Browser is Firefox (just like mine). Cookies have been deleted several times without solving the problem.

Your help/ideas would be greatly appreciated.