Why does my iphone 4 say This accessory may not be supported?

When i plug my phone in to charge it starts the charge for about 2 seconds and then the message "This accessory may not be supported" appears and the phone stops charging. It does that every time I try to plug my pone up to charge. Once my phone turns competely off it takes 4-10 hours to turn back on and when it does its only has 4% battery. Why does it do this? I cleaned the port, changed the charger(with an official apple charger) but i'm still having the same problem. I'm on ios 7.0.3. Does anyone know what's causing this problem?

Lots of info on this on the internet: http://www.gatorspit.com/tips/iphone-wont-charge.html