Folder Status Does Not Update When New Mail Arrives

[Rafael]

Some of the outlooks 2000, xp and 2003 we have in our
network do not have their folders` number of unread items
updated when a new mail arrives in that folder.
If I click another folder, all the folders have their
stauts up to date.
This only happens when the Outlook is open, when it is
minimized, it works properly.

Has anyone go under this before ?

Thanks a lot,
Rafael.