Imagio marketplace not working after switch

[geckobreeder88]

Ok so i switched my imagio vodafone verizon to att. I unlocked my sim and all that. I can make calls, receive calls, browse the internet on internet explorer, but i can not access the marketplace. I wanna be able to use a marketplace to download apps. Im using gsm. Is there a rom or anything I can do to get a windows marketplace, or an android one? Help much appreciated. Ive done custom roms before on a G1 and a few others. This phone is new to me and changing carriers is too.