Metal pin fallen out of iPhone

[md42]

Hey, i dropped my iPhone 2g a few days ago, and ever since then it comes up with the "this accessory is not made for iPhone" or whatever, i've got past this replacing a file on the phone, but now trying to play music via hi-fi and the usb hub thingy doesn't work. it still plays music normally and through headphones.

I opened up the phone because it was rattling and this pin fell out lol, its only 3mm long, but i have no idea where it goes so can't put it back in which might help fix the usb problem.

Does anyone have any idea of where the pin goes? i can live with my phone being like this, but i'd rather put the pin back if possible.

Thanks