I really appreciate your help tendriver
When I do as you suggested (plug SD card in tomtom, open TThome, click operate my device) it immediately shows the tomtom screen and says no maps found :(
However if I disconnect the tomtom from the pc and go to switch maps on the device itself, it shows the 3 maps I have installed (Eastern Europe 860, Europe West 870, South Africa Swaziland and Lesotho 870)
Does this help? it's like TThome doesn't register maps are on the device but on the device itself, everything is ok