Thanks for checking that for me. I may go back to TMobile this weekend and see if any other Vibrants have the same issue. I am imagining they do but it's worth a shot.
Now another question...
Can you open up your dialer and type in *#*#1472365#*#* and a secret GPS settings screen comes up like on the Vibrant?
If so can you go into "Application settings" and see what it says under "Operation Mode"? The Vibrant says Standalone
Then go out of Operation Mode and go into "SUPL/CP Settings" and see what it says for "Server" test? The Vibrant says www.spirent-lcs.com
and finally is your port set at 7275?
Just want to see if the ATT phone is setup any differently.