Exchange 2010 ActiveSync "Cannot Connect to Server"

I'm a Desktop Support specialist in San Antonio. I'm having issues with my Iphone 4 with the latest 4.0.2 update and connecting to my exchange. My manager, who is the only other IT person here, set up the Exchange and so we are confident that my account settings mirror his in exchange as well as AD. Yet his account will verify to the Exchange and mine will not. Anyone ever seen something like that. Apple Support says its my exchange yet my exchange allows other people with Iphones to get on with no problem. Please advise if you have any helpful tips or tricks to get my Iphone 4 (v 4.0.2) to connect to Exchange 2010 ActiveSync. Thanks