desktop alerts Outlook 2007 not working

I can't for the life of me get desktop alerts work on Outlook 2007 on Windows 7. I'm using IMAP (with zimbra - that shouldn't make any difference though), I didn't have any addition rules, except the "clear categories" default rule, which I deleted anyway, so that it wouldn't affect the desktop alerts. I have this problem on a lot of computers with the same configuration. The Notification area shows all icons (I don't like to have hidden items).

I went to Tools - Options - Preferences - E-mail Options - Advanced E-mail Options. I checked all boxes, including "Display a New Mail Desktop Aleert (default Inbox only)". The duration and transparency are default (7 seconds, 20%.). If I press "preview", it works fine.

I'm thinking that the problem might be related to what outlook considers to be "default inbox only". As you might know, outlook 2007 always creates a default personal folders pst, which is local, and another mail database for imap. The envelope in the notification area does show up, but when I press it, it selectes in inbox in the personal folders, which is rather useless. I also set Outlook to start direct into the IMAP Inbox, instead of the Personal Folders Inbox, but I don't think that makes any difference as to what it considers "Default Inbox".

Any ideas?

There's nothing marked as 'default'. It's just that the "Inbox" folder looks different from a usual mail folder, in that it has an envelope as a symbol. If there's anyhwere I could change the default inbox, I'd really like to know, but I'm not sure that can be set - at least not in Outlook 2007.

I was able to solve it using rules for all incoming e-mails. Thanks.