Hey guys new to the forum but not iphone... I have had all of the iphones since the 3g and up until today the iphone 4 on AT&T. I switched to VZW and the issue im having is that i have excellent 3g coverage in my area on vzw.. Until i get in my house that is where it flips back and forth between 1x and 3g. I was succesfully able to do this on my AT&T ip4 using this method:

Phone: FORCE 3G MODE ONLY

intall gtxtedit from cydia
open gtxedit from icon
load /var/preferences/csidata

Inside csidata you will find the following line:

GsmRegistrationModel::fRatSelection=0x1
The following values apply: 0x0(EDGE ONLY), 0x1(EDGE+3G), 0x2(3G ONLY).

Select GsmRegistrationModel::fRatSelection=0x1

Change 0x1 to 0x2 and save the file
save to /var/preferences/csidata when asked

Reboot the phone.

Change the same file back to 0x1 and save to revert. Remember its the 1st one on top of 0x2 and you are basically making both 0x2.

Below is the screen i see on the VZW ip4 and i figured it would be different on CDMA but i dont know what number i would use on the registration line underlined below... Or is there a different method to use for the CDMA version?? Thanks in advance for your help!!

CallListModel DtmfType=0x0
SettingsModel::UnconditionalCallForwardingActiveVa lue=0x0
TraceModuleExtreme DIAG::fEnabled=0x0
TraceModuleExtreme DIAG::fEnabledDuringSleep=0x0
TraceModuleExtreme DIAG::fStopWaitTime=0x8
TraceModuleExtreme DIAG::fMergeSnapshot=0x0
TraceModuleExtreme DIAG::fHistoryCapacity=0x80
TraceModuleExtreme DIAG::fStallProbeInterval=0xea60
TraceModuleExtreme DIAG::fStallProbeBehavior=0x0
TraceModuleExtreme DIAG::fMode=0x0
TraceModuleExtreme DIAG::fFile=default
TraceModuleExtreme DIAG::fShouldGeneratePlaintext=0x0
TraceModuleExtreme DIAG::fShouldRetainRawFiles=0x1
TraceModuleExtreme DIAG::fShouldTranslateLogs=0x1
TraceModuleExtreme DIAG::fMessageConfigView=0x3
TraceModuleExtreme DIAG::fLoggingConfigView=0x3
TraceModuleExtreme DIAG::fEventConfigView=0x3
TraceModuleExtreme::EURCoreDump::fEnabled=0x0
TraceModuleExtreme::CSILog::fEnabled=0x0
TraceModuleExtreme::CSILog::fHistory=0xffffffff
TraceModuleExtreme::fExternalUSBTracing=0x0
RegistrationModel::fRatSelection=0x5
SettingsModel::CallWaitingEnabled=0x1
SettingsModel::CallingLineIdRestriction=0x0
GsmRadioModule::fPreviousBootUptime=0xeb5