I can download free and trial apps with no problem. But if I try to Buy an app through the store, it takes me to a page asking me to sign in with my Google account. I do that (even though I'm signed in already, and all my Gmail is synching just fine) and i'm brought back to the Buy screen in the Market Place. If I click on Buy, it just brings me right back to the screen asking me to sign in!!! How do I purchase something?