about two days ago whenever i plug my iphone into my hu it overrides the hu and blasts the iphone out at top volume. it will begin to play the music on the iphone even though i have the other ipod selected. even with mute on it still does this.

I believe this is the AppSoundMixing setting in the system menu change setting to AppSound Mixing to low. This setting allows you to hear your Apps (Navi instructions) whilst listening to radio.

If you launch music using CarMediaPlayer app the AppMode will takeover the HU, and you will get full volume. Close all AppRadio apps running in background on iPhone and try again.

Personally I only use AppMode for Navi the HU does a good job of playing iPhone music and video without the help of AppRadio

well whenevr i plug in the iphone it does this, and i find that it has dock connector selected in the when i double click and slide all the way to the left. when i put it on the avh-8400, everything is back to normal, except if i am listening to pandora. when listening to pandora, if i switch to appmode, it sounds like ass and it seems only the front speakers work when this is done