I recently jailbroke my iPhone with the 3.1.2 firmware and the 05.11.07 baseband. I have installed some cydia apps on the phone and it was working just fine until earlier today. It is showing full signal with 3G but it will result in spotty phone calls (only successfully makes a call maybe 1 out 4 tries), doesn't reach the internet without a WiFi signal (I am getting the "Cannot activate cellular data network message) and text messages take forever to send and sometimes fail to be sent. I have experimented with tethering on the phone but I have not had transfered anymore than 5 MB of data in the past 3 days on tethering so I doubt AT&T is messing with my service or anything like that. EDIT: Now when I switch to Edge my phone works perfectly and I get full bars. However, when I switch back to 3G I lose service completely and have to switch back to Edge and then reboot my phone to get it to work. I've never had this problem before as I am in an area with 3G coverage (Santa Barbara, CA). I forgot to add that I downloaded the AT&T APN settings from unlockit.co.nz. It is still on the phone. Should I remove that? Does anybody have any ideas on why this may be?