Hi Mike,
I shot you a response to your email, but thought it would be good to discuss this here as well in case we discover something that might help others. Here is what I wrote:
Could you try downloading this .img file and copying it to your device:
http://www.switchbacks.com/downloads/NW_Trails_v1.72.img? To be safe you will want to turn off or remove your other mapset just so that we can eliminate any potential interference from that.
If you still can't see the trails with this install, then we can look at what might be going on with the device settings. I have a 62S here at work that I can experiment with.