This just started happening so I think its a little weird. When I plugged my iPhone (have the iphone 4) into the USB port, it won't play my music I have playing from my ipod. It just tells me I have a docked accessory. When I change it to blue tooth nothing... it just gives me the screen like its trying to sync... It just does this when I play music from the ipod but not anything else like Slacker radio.

I was only using the usb to mainly charge my phone. I play all music via bluetooth because to me it just seems the easiest...Is there a fix? Or do I just have to buy a charger. It has been working fine and today is the first time it started doing that.