Faulty charging problem WEIRD!

I have a white iPhone 4 16gb (jailbroken)

whenever I plug in my charger whether it be computer or plug the Phone won't recognize it.
But the weird thing is that when the phone is dead the iPhone charges (WTF)
so I left the phone on charge all night and in the morning its at 100% (WTF)
iTunes won't recognize it in DFU mode or normally for that matter. the phone is still under warranty but I don't want to take it to the store because it is jailbroken and it will void my warranty..
any ideas?!

PLEASE HELP!

 

PLEASE HELPP!!! I need a way to restore it or unjailbreak it in a way that I can take it to apple! HELP