I'm a Google Apps user. The short version of that means I pay $50 a year to use my domain as a shadow Gmail account plus calendar, contacts, and a bunch of other features that aren't available to the free Gmail folks.
I just purchased a new app in the store; my first experience. When I got past the "Buy" screen and the "Permissions" screen, the market took me to a "CREATE ACCOUNT" screen for Google. I clicked that I already had an account and used my Google Apps login, which is NOT THE SAME LOGIN as the Google Gmail Free Account login.
i got stuck in an endless loop asking me to create or login to an existing account. My credentials did not work.
I finally tried logging in with my FREE ACCOUNT CREDENTIALS which I never use. That account only gets spam and I check it maybe once a month, but it IS an active account.
When I logged in with my FREE ACCOUNT CREDENTIALS, I was taken to the credit card payment screen and completed my transaction, including seamless downloading and installation of the app.
Just a word to us Google users who don't use the Free Account to login. It won't work yet.
This is interesting since my "paid Google App" login credentials work perfectly to get my email, calendar, and contacts "pushed" to my Droid.
Enjoy the journey,
Recovering Storm Abuser