My first generation iPhone running firmware 1.1.4 hacked to work in Sri Lanka, started to give trouble from a few months back, and taking almost a day of being kept switched off to magically recover! I never understood why a 8hr switch off was different to a 10 minute switch off.. but then again, people even suggest keeping the iPhone in the freezer to make it recover :).. I only tried that for 5 minutes..
Anyway on the 10th of February, I upgraded to the new version 2.2.1 firmware.. and immediately realized I had done something really bad.. by Wifi was not working at all.. I then tried down grading to 2.2 - but still no luck.. then I tried going back to v.1.1.4 by even installing an old iTunes version and downloading the ipsw image files.. but trying quite a lot of hints, I was never able to get my modem firmware downgraded.. it had got to 04.05.04_G and I was stuck! Then things got even worse.. the phone would not ring.. but silently record missed calls.. then I gave up everything, and was waiting for someone to find a fix patiently.. I realized that the phone does ring, when its kept unlocked - but that soon drains the battery.. another option was keeping it connected to the charger.. so I did both of these until today the 6th of March..
.. and today, I felt lucky! suddenly.. I felt my phone ring again!.. and I tried it a few times to make sure.. and yes, it has started to work again :).. then I tried my Wifi.. and thats back too! I hope this will help someone else who is like me to get back their iPhones.. the secret being patience! I'm happy to have a real ringing phone back with me.. and I will not try any more upgrades for a loooong time.. its currently running 2.2.1(5H11), Carrier 2.9 and Modem firmware 04.05.04_G