every time i start my car up it plays the last source by default while it starts up. this is great! i usually have it on FM most of the time. so it plays the radio, but once it reads the USB device, it switches over to that. is this some auto play feature, can i turn it off??? it's really annoying when it changes audio by itself. besides the freakin 5 minute startups and the extreme slow response to touch comands, this unit is: so-so, not the greatest. better than stock i guess.

It has to do with your usb drive. I spoke to pioneer because I had a problem updating my software on the x910 so they told me that certain company cards will not get detected by the system until completely booted therefore mine would not boot up in update mode. So I am assuming you have the same problem cause when you start up it defaults to last played radio then when its done booting it discovers a new item in the usb so it jumps to that just like when you insert a CD.

Why don't you just turn off the source before you turn off the unit?

Go to source and turn everything off at right bottom corner?