Installed Mozilla/5.0 (Windows; U; Windows NT 5.1; cs-CZ; rv:1.3) Gecko/20030312 on WinXPprof on a small net downloading mail from local server with WinRoute running. When new mail is downloaded and remains in the Inbox folder of the account, the "Inbox" does not turns bold as well as number of the new messages does not appears untill I click on the Inbox folder.

Seems to me that with me this only applies to the position 2, 3 and 4 in my acoount list. The first account is as i remember correctly updated all time. But with the other ones - if i check for my Mail on startup. I just got one mail for acc 3 in list - the mail notification flashes in taskbar down right. But no special icon or bold font at the inbox. Maybe its a problem that only the selected account at the moment of the receipt is correctly updated.

I have had this same problem myself for months and months under Linux (including Mozilla 1.4). As you describe, i have the problem only on secondary accounts. The first account works fine. Furthermore, it's only a problem with the inbox, not subfolders to which messages are routed automatically by filters. Please change OS to "all".

*** This bug has been marked as a duplicate of 186573 ***