I have an iphone 4 unlocked with ultrasn0w and jailbroken. My carrier is Movistar in which 3g services do work.

When I'm home I sometimes get 1 to 2 bars of signal and about 10 minutes later I get 4 to 5 bars. This happens all the time and in different places. My 3gs always had full signal strength at home. Never ever had a problem with my 3gs with signal bars or making calls I know Apple recalculated their signal bars to show more acurately but this has become a real problem for me.

But while at home, and when my ip4 shows 1 signal bar I can't make or receive calls without getting call failue. My wife's 3g shows full signal and can make and receive calls with no problem at all.

If I try making a call or recieving a call with one signal bar I get a call failure and my phone loses the ability to make or receive calls.... So I have to try rebooting or turning off and on or ejecting and reinserting sim till I get signal bars again.

When I finally get signal bars again I have to check my 3g services because sometimes I get an error saying it cannot connect to internet or no network services. So I have to go back to turning off an on or ejecting and inserting sim till I can get the 3g services working again.

REALLY REALLY annoying!!!!!

I did cut my sim card with scissors but as far as I was concerned I did a good job cause the cut sim card looks like the at&t sim card.... At least as far as the eye can see when you closely where the sim contacts are and the overall size of the sim.