Is this a work computer or your own computer at home?
I suppose you could try toggling the
Show the mail icon in the notification tray off, then back on, but your best bet would be to setup the rule in a
new Profile. Yes, Outlook would create
one new .pst file. Which can later be deleted.
Though, if you don't want to do that, the only other suggestion would be to run the
/cleanrules switch when starting Outlook 2003 and recreating your rules.
http://www.outlook-tips.net/howto/commandlines.htm
As for the link you posted, did you migrate from Windows 2000 to Windows XP SP2 using Exchange Server? If not, I don't believe it applies in your case since you
are seeing the mail notification icon when messages are received in the Inbox.