Hello all. I do not know if anyone could help: the matter is very specific and it relates to reception issues on iPhone 3GS. I have one bought last frebruary and now it runs iOS 4.0.1 Jailbroken with Jailbreakme.com. The process was successfull and everything is ok. The phone always had an issue with signal: in covered areas, some houses and buildings and in some poor GSM coverage areas, calls are not allowed and possibly drop if ongoing. After a deep analysis with Field Test for iOS4 and Signal.app in Cydia I found that signal is present and active, maybe low, but the important thing is that below -81 dbm (RSSI = 29) the problems begin to show up. No problems when RSSI is over 30 (and therefore reception is over -80 dbm thru -51 dbm), but when the signal goes below that threshold the calls are not allowed. Keep in mind I bought the phone with iOS 3.1.2 and apparently the problem was already there, even if at the time I did not check the situation with Field test Mode. Then I went thru 3.1.3 and finally 4.0.1 with the Jailbreak. I also restored the phone once, but restoring a backup as well, and no changes were appreciated in the phenomenon. Can we now say that the signal is there while the baseband (05.13.04) is not properly managed ? Is there someone that experimented a similar specific issue ? And finally: would there be a proper solution ? I would get back to iOS 3.1.2, but firstly I'm not sure SHSH saved on Cydia will allow me to do that, as I was able to save the ECID for 4.0.1 and secondly if the phone already had this issue with the original firmware the operation is not worth being done. On the other side, deep analysis of teh signal and baseband done by Anandtech, for example, have been detailed for iPhone 4 and even if the firmware was the same it appears the behavior was pretty different, being apparently possible to call on iPhone 4 even with signal ranges to -100 dbm. Can someone share his experience, if some present ? Many thanks in advance. R.