You erased and replaced your certificates when you reinstalled the OS. You left out a few key details:
1. Are you using UMA when this happens?
Does it happen on GSM/EDGE?
Does it only happen at one location Work or Home, or also at HotSpots?
Once you answer the above we maybe able to assist a little more. You may want to exchange the unit with T-Mobile.
Also you can not make a UMA call without the certificates.
Last edited by TroyDBrown : 12-17-2007 at 01:58 PM.