By the way, Steve, you can download all the maps from this page:
http://www.navicoretech.com/Consumer.../en_GB/tablet/
so if you have fast internet, maybe that's the way to go. It's for linux users, but I don't see why it shouldn't work on windows too. After starting the program on the device, you'll only have to enter the license key and you can use the maps.
Btw, I contacted Navicore once and they replied the next day. (I was hoping to get the traffic service running, but unfortunately they have not implemented that on N800.)