Hi, in the past few week I've been getting the "Chaging is not supported with this accessory" message on my iPod touch 4g. It used to only come up occasionally but know it comes up about 5 times each charge. I'm using an official apple wall charging adapter (don't know exactly what they're called). I have dropped my iPod numerous times, but I don't think that's what's causing this. Any help would be appreciated, thanks.