Vista - Outlook 2007 won't open

Hi All,

I've been having a problem with my Outlook 2007 not opening after it's been closed. This just started yesterday. Specifically, when I start my computer in the morning I have no problem opening Outlook. If I keep it open it seems to work just fine. The problem occurs once I close it. If I try to open Outlook after it has been closed, it won't open. Initially when I attempt to open it I get the "spinning blue circle" which gives the impression that's it starting to open, but after about 5 seconds, the circle disappears and Outlook doesn't open. I don't get any kind of error message whatsoever.

If I restart my computer and start Outlook again I get a message saying that Outlook didn't open properly last time and I'm asked if I want to open it in safe mode. I've opened it in safe mode (and regularly) and it works fine. However, once I close it, it will not open unless I restart my computer.

I've put the Office 2007 disk in and chosen the repair option, but that didn't do anything. I can't figure out what could have happened. Any help would be greatly appreciated. Thanks!