I recently bought the Seidio extended 3500 battery. I put the new battery in last night, used it for only a few moments but it seemed to work fine. After that I turned it off to charge, as they recommend. It charged overnight, and then when I turn it on this morning the phone seems to work fine except no 3G. In the Wireless & Networks tab the Mobile Network checkbox is checked but constantly greyed out and says "Turning on . . ." I don't see how the battery could be at fault seeing as plenty of other people have used it seemingly without issue, but seeing as that's the only recent change I've made to my phone, I can't think of what else it would be.
If this is relevant at all, the WiFi works just fine.
If this is relevant at all, the WiFi works just fine.