Thank you for your replies!
I think when i use the device
either by batteries in music-mode,
or in usb-mode connected to the computer, the problem can be solved with a diode.
But sometimes i would also just like to power the device via usb (without batteries at all) and still use it in the music-mode. So to be able to switch from music-mode to usb mode while connected to usb would be nice... do you think it is possible to assign the different modes to a button or a button-combination?
Can i make this software-patch myself with a very basic programming knowledge or do you think not? If it's not all too difficult (but too difficult for me

), could someone write a patch and provide it in the patches-section? I think other Archos-Jukebox users would appreciate the feature as well...
Thank you for your suggestions...