Hi so I installed BaseCamp, not familiar with it but this is what I did.

First I tried to open the .img file that I have saved on my PC from the SD card MapSource installed it on and Base Camp does not appear to support opening that file type.

Next I connected my Garmin to the PC via USB and said receive from device and it imported the map from the GPS and I could select the map in BaseCamp and the trails are on it. So the only thing I can think of that is causing the issue with my maps is I am selected to create an IMG file from both a TOPO map and my trails GPX files and I wonder if the topo map is being layered over my gpx trails file is that possible?

Otherwise I wonder if the GPS is like the Drive 61 models that the firmware only allow displaying Garmin map files...

Thanks ~ Phil