Microsoft exchange server will overwrite your phone with permission settings if you don't set your phone "screen lock security" settings first. If you haven't already, reset your phone to it's factory default (make sure you have all the downloads and user settings backed up somehow so you can reinstall if needed). When I reset to factory default my "Market Place" apps came back up.
After you go through the startup process and before you set up your corporate sync or reinstall anything, go to settings/location and security settings/security change screen lock. The "None" SHOULD NOT be greyed out and you will be able to tap this and disable the login screen password/pin. After you have done this, the pin that is required to unlock your phone will not be activate. Now go and set up your corporate sync.
I don't know why this order of things is needed, but would have been nice to have known before I set up the corporate email account. It would have maid things easier.
Worked like a charm. I followed wpbcadmin's instructions, but instead of starting with a reset, I deleted the exchange account. The I followed the rest of the instructions and finished up by re-adding the exchange account. No more PIN screen. Thanks for the help!
