CDX-GT540U - Usb Problem

[Daverin0]

It has been fully installed and set up exactly as shown on the instructions. The radio works perfectly but for some reason when i plug in my iphone to the usb slot to play music through it the screen shows "usb no support". In the instructions manual it says when the screen shows this it means the equipment isnt  compatible which i know isnt the case as i know someone who has 1 and they play the iphone through theres. The strange thing is when i plugged in an ipod out of curiosity, it worked. Anyone got any ideas what i can do?

[Drumzman]

Just a thought, but what is the file format of the music that you have on your iPhone?  Have you checked that it is a compatible format (it should tell you the formats you can use in thr manual for the GT540U).  Also, the person you know that has connected their iPhone, do they have exactly the same Sony model as you?  The reason I ask is that I know Sony do some radios that are specifically compatible with iPod/iPhone and actually have the Apple connector that plugs straight in, and your model is not one of these I think.