Mail Not displaying at all

Help!!-I have no display of the mail app other than the header and the badge on the dock with the number of new mail in my inbox. I migrated all my data and settings from my old macbook with snow leopard to my new macbook air,( first Lion now ML). On Lion I had the same problem, but thought that ml would solve it... not! I have tried a few of the tips on here with a database rebuild, I still get no display at all. On the same machine I have set up a 2nd user account and the mail app works just fine, its very frustrating trying to get mail to display on my main account,- the activity and connection doctor show its connected to the server, I can select everything from the top menu bar other than mail preferences and every time I try to shut down I cant because of mail, end up having to force quit it---any ideas or help?? Thanks