Accessory compatibility prompt iPhone

Hello everyone, first post. I know this is a known issue, but its a variation on a theme, so please read the whole description before writing it off.
Whenever I plug my iPhone in to almost any adapter or dock, even with a charge converter, it will work fine for about 10 minutes. After that, the music pauses and the iPhone gives the compatibility error. I press any button (either way, it exhibits the same behavior) and start the music again. Then after about 3-5 minutes, it pauses and gives the error again, and again after a minute, and then every 3-5 seconds. If I remove the iPhone from the device for about an hour, and try it again, the cycle repeats itself.
Ive tried cleaning everything thoroughly, and checked with those who support two of the docks and they say at the bare minimum they support playing music.
To boot, I also got a Apple bluetooth headset and it will allow me to make outbound calls, but it rarely allows me to take incoming calls.
Im using a brand new iPhone 3G 16GB running firmware v2.2.
First, is anyone else exhibiting any of this behavior? Second, does anyone think its a hardware issue? Third, can I do a swap at the AT&T store. I just got it from there about two weeks ago.
Any help would be greatly appreciated. Thanks!
MacBook Mac OS X (10.5.6)