im using yessim firmware 2.4 beta c. Im sure its pretty much the same as what you speak of. It has edge and everything works, but its lost network a lot whenever I lose service somewhere and then wont get it back until I put it into a tmobile phone and back into the iphone. Someone told me to take the carrier setting off of automatic and put it on Tmobile and this way it wont try to look for another network when it loses service, supposedly make it regain service after I pass through the bad signal area.
Hope this Helped.
BTW this is where I got it and it was 59 bucks...
YESSIM.com - Universal unlock sim - Unlock all existing mobile with one sim
they have a support forum there where you can look and see others issues and how they solved them.