I have an iphone 3G which is jailbroken and I use my 3 sim in it. It has suddenly developed internet connection problems where I am unable to connect to the web or check my email over 3G. I have full receptions bars so it is not a poor signal issue. It also works fine over wifi. Occasionally, I will get connection for a few minutes then it will go down again. I have tried respringing, rebooting, different APN settings etc but none works permanently. I get a message saying "Safari could not open the page because the server stopped responding". For email, it says something like "cannot get mail. The connection to the server failed.
Can anyone help? Just to be clear, I have been using it since christmas and the problem only started last Thursday or so.