Gigabeat stuck. Please help if you can.

[DonQuixote]

I need some help with my gigabeat f40, and I'm hoping someone here can help.  The device is stuck in USB mode.  When I turn it on it boots into the grey screen with the words USB Mode on it, whether or not it is plugged into a cable/computer.  When I do connect to a PC, it does work as a USB drive as normal, it just never gets out of that mode so I can use it as a music player! 

At this point, I feel like I've tried everything- I tried restoring the original firmware- that was a no-go, as it gave me an error (c00f74e4), and I had to dismantle the thing and do the unplug-the-harddrive trick to get it back into USB mode (the normal 'menu' USB mode didn't work).  Also, when it gets stuck in a mode like this, I hve to turn the battery off to get it to reboot.  Of course I tried putting the latest version of rockbox  and the bootloader on there, neither made a difference (whether installing manually or using the automatic installer). 

The only thing I can think of now is if someone has or can modify the bootloader to completely ignore the USB mode- I figure that I can always hold the menu button to boot into the recovery mode if I want to put new stuff on it.  Any help with this or any other ideas are much appreciated.

[markun]

Is there some dirt in the USB and or dock socket which could cause this?

[DonQuixote]

nope.  That was my first thought, too.  I cleaned it pretty thoroughly.