nuvi 1490MT All latest updates installed.
1) Express doesn't recognize the 16GB memory card--keep getting a "not enough space" message. Absolutely no way to overcome this bug. Workaround was to plug card into directly into USB and download to computer pathing to that drive letter. Express still doesn't see it but I do get an acknowledgement that all maps are current along with updates. Who knows, maybe they are--maybe they aren't. Can't find a way to confirm it. Boot Camp says loaded maps are not "lockable".
2) Now, my unit simply gives me the message "No Map Data". There is no way to get past this stage so the 1490 has now become a hockey puck. One solution found is to remove the battery and reset everything. I would do that if I could find a screw driver that fits those screws. Still searching my local stores.
I have to say that this map update process is the most frustrating experience I have ever had with any electronic/frimware/software device.