Hey guys I really need some help I've had my ip4 for about 5months now and I've connected it to two computers over that amount of time and have bought to USB cables for it. At night I charge it from my wii which I moved next to my bed. Now about 3-4 days ago I plugged my iPhone into my laptop one of the main computers I've plugged it into it is a hp windows 7 64bit and I got a pop up saying that USB device not recognized this USB device has malfunctioned etc. So then I tried a different device in that port and it worked so I tried all my other ports and got the same message so I tried the other computer and same thing so then I tried my wii to see if it would charge it charges but it takes almost 5min to an hour to start charging . Only thing I've changed recently was I updated itunes and I synced my music with mediamonkey instead of iTunes and it was still connecting after that.
It might be because you plugged it into the Wii, but there is no way to know for sure, I suggest to do a restore. If that doesn't work. I would take it to the Apple Store!