My DROID will not charge from the docking station or from any USB cable connected to the computer, but it does charge when I plug the USB into the wall adapter.
Update: It does charge through the USB on my laptop, but not on my desktop.. I haven't changed anything for a long time except getting a new keyboard so I am not sure why this would occur now.
could it be that your USB on the desktop is an older version (like 1.1)? I haven't tried in anything but 2.0, but have at times gotten the "this device could perform faster..." yet it still charged (but I figure b/c it's still 2.0 it's enough juice)