Hooray!
That did it. I knew about the GMTK, but didn't know about the Device Manager.
After playing around with it, I discovered the "Delete GarminDevice.xml" feature. After running that Basecamp re-discovered my device, re-indexed the maps, and I've been good to go ever since, easily moving maps back and forth between the device and the card, and everything just works.
Thanks much!
That did it. I knew about the GMTK, but didn't know about the Device Manager.
After playing around with it, I discovered the "Delete GarminDevice.xml" feature. After running that Basecamp re-discovered my device, re-indexed the maps, and I've been good to go ever since, easily moving maps back and forth between the device and the card, and everything just works.
Thanks much!