I upgraded the Navicore using: SE_Navcore.9.205.547817_32mb_devices. The navicore would boot and work just fine with my tom tom and read the original map just fine. I did not check for GPS signal.
I tried to install maps 860 3100 and 860 3101. I used an installer and I would get errors that the map could not be used on my device.
I restored from my backup the map directory. The tom tom started up and ...