Location services cause 3gs to lost signal

[basmith92888]

I have unlocked my iPhone 3gs using ultrasn0w and everything works fine except for my location services. Every time my phone tries to find my location it drops the signal and says, "Could not activate cellular data network." This will happen on the very rare occasion when I am using Safari or other wireless data apps, but it happens every time I use Google Maps or other location apps to find my location. It will initially find my location without any issues, but after about 30-45 seconds it brings this message up and I temporarily lose all data services. Does anybody have any ideas on how to fix this and is anyone else having the same/similar issues?