LDAP Directory? It won't go away!

[Mountaineer]

I recently installed Office 2007. Every time I open Outlook, I get a popup asking for a username and password for an "LDAP Directory." Clicking either OK or cancel will make it go away and Outlook opens normally then, but it's annoying as heck. Can someone PLEASE tell me how to make it stop doing this? I posted to another board and got no responses. I tried to use Microsoft's support and they were do-less. I have attached a shot of the popup that I am seeing. I've tried everything I can think of - this HAS to be something simple, right??