Wml?

Dont know if this is the correct forum. I need some help with WML.
I have written a mobile app allowing users to log on and view detials. The app basically consits of asp pages with wml inside. I have tested it with Winwap, Openwave simulator, and nokia toolkit, and it works fine, but when I try to use a actual mobile phone it retrieves the first two pages and then either gives errors or just hangs.

Is there specific settings on phones that needs to be changed?
All my MIME types are set up correctly on IIS!