Modifying /etc/sudoers will not prevent communication loss - it will only allow Maemo Mapper to "recover" from that state by resetting the bluetooth radio and re-connecting. This "hack" is not technically guaranteed to work, since it relies on the bluetooth subsystem itself recognizing the fault condition and informing Maemo Mapper that the connection is bad (which is, in my experience, normally the case).

If you don't modify /etc/sudoers, Maemo Mapper just tries to re-connecting, but the whole problem is that, in this particular crazy situation, the bluetooth radio stops working entirely until it is reset.

Short of enabling debug, the only way I can think of to verify that the bluetooth radio was actually reset is to keep another bluetooth device connected to the Nokia 770 and see if that device gets disconnected (due to the radio being reset).