I have an US 1.1.2 OTB running 1.1.3. After ZiPhone jb, activation and unlock it worked fine (voice and txt) with an UK O2 PAYGo contract. Today I switched to a monthly (non-iPhone) O2 contract and as a result sending txt doesn't work anymore (GPRS/EDGE and voice does). I also can't find the O2_UK.plist file in /System/Library/Frameworks/CoreTelephony.framework/Support/.
Thanks a lot!