Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Everyone gets that or just you?
Cleared your browser cache?
I see you're using Vista - did you install KB911829 on the server?
http://www.microsoft.com/downloads/...8A-08EB-4976-BC68-A03EBE3A2552&displaylang=en
Make sure all Exchange boxes are on the same service pack. There is a kb article about that somewhere on MS site.
Try searching for OWA "loading..."
I was having the same issue with my exchange servers, seemingly at random with users.
I ended up going SSL w/FBA and it stopped, and made the users happier (a custom company login screen with fancy colors makes end users happy)