Network problems with iOS 4.2.1
I am using a factory unlocked iPhone 4. Initially, the phone came with iOS 4.1 (not really sure about the baseband) and I jailbroke it successfully with Green Poison. There were no problems at all but after the release of Green Poison RC6, I decided to update my firmware and re-jailbreak. I am currently running on 4.2.1 with 03.10.01.
The biggest problem I faced after this has to do with the mobile network. I tend to receive messages late (ranging from few minutes to few hours) if the 3G is turned off and I'm running on Edge/GPRS. Sometimes, the message wouldn't come in at all until I receive or make a phone call. Another discovery was that the reception would be fine if the Wifi reception is good. I've somehow found a way to determine if the messages are coming in or not. I'm using BiteSMS 5.2 with delivery report installed. If I am getting a late delivery report for the message I send out, the reply that I receive will definitely be late as well. However, the other party on the receiving end will not be getting my messages late. This means that the only problem here is with my phone's reception.
What's confusing is I don't seem to have this problem previously when I was running on 4.1. There also seems to be no problem if I restore it to the factory settings of 4.2.1. So right now, I'm wondering if it's a problem with the jailbreak or the baseband. It's really annoying because most of the time, I have to keep the 3G on and this drains my battery life. Sometimes, I cannot even receive or make calls as well. Need some help on this.