Bluetooth/aux/usb Locking Up Stereo

Hi,

I recently bought a 2009 Ford Focus Titanium 1.6TDCi which what I believe is the Travelpilot FX headunit. I have recently been having intermittant problems with the stereo that i'm hoping some of you may have seen.

When i bought the car, the first issue i found was no right audio from my Ipod, USB stick or Aux device. 3 trips to the Ford dealer and they changed the Bluetooth device (the Aux and USB ports are part of the Bluetooth kit apparently). All was well for a few days - then the fun began.

I have been experiencing the following intermittant problems:

* Headunit locked up after hanging up a call received through the bluetooth kit. The RADIO, CD/AUX/USB buttons dont work at all and no sound heard from the stereo. The PHONE button works but cant hear any sound on calls. The NAV and MAPS screen functioning fine. Seems to be just the audio side of things that have frozen. The only way to resolve the problem is to turn the engine off, lock the car, and leave for 10mins. Sometimes a constant humming/buzzing noise can be heard from the area of the headunit/bluetooth device.

* Happily driving about with my Pure Highway DAB unit plugged into the AUX port working fine. I pop in a shop for a min, come back out, start the engine and the stereo locks up with tth same symptoms as above.

* Get in the car, turn on the stereo, select USB (i have a USB stick full of music) then same thing happens as above.

Since these issues, i have upgraded the firmware to the latest on fords website hoping this might help - it does not. Now my USB stick isn't recognised at all even though its formatted to exFAT as its 64GB.

Any views or ideas guys?

I have a couple of months left of the warranty left on the car but have a feeling Ford wont find the issue as its fairly intermittant.

Regards

Dan