Good spot with the gconf setting there! I've been looking for that one for a while now (particularly handy for the USB Mouse app since the tablet detects the mouse as a HID device and disables the onscreen keyboard!).

I can shed some light on the strange/random USB keyboard issue by the way (as far as bluetooth, I don't know I've run into it once or twice myself, but I imagine it's something somewhat similar): IF you're using USB host mode (especially if you're using the auto-switching OTG adapter) and you take the device out of host mode BEFORE disconnecting the keyboard itself from the USB bus, the kernel never receives the USB disconnect signal, so it never removes any of the sys or device entries for the keyboard (it thinks it's still connected). It's a problem that we've run into for all of the USB devices, and the only really viable solution at this point is to be careful with how you handle things. For example, if you've got the auto switching OTG adapter:

This scenario will cause the problem every time:
- Connect OTG adapter with USB keyboard plugged into it
- All works, you type, yada yada yada
- You unplug the OTG adapter with the USB keyboard plugged into it
- Onscreen keyboard will not return.

Compared to this which will never cause the problem (as far as I can tell):
- Connect OTG adapter with USB Keyboard plugged into it
- All works, you type, yada yada yada
- UNPLUG USB KEYBOARD from OTG adapter, leaving OTG adapter sitll connected to tablet.
- Wait a second (well probably by this point not really required, but you get the idea)
- Disconnect OTG adapter from tablet.
- Onscreen keyboard will return normally.

Now, that should only affect USB keyboards, since it's a USB problem that's causing it... BUT, I would guess that if for some reason the BT keyboard looses connection or the tablet doesn't "unpair" successfully with it, you'll run into the same scenario...

-Rob