It appears like most of the terraserver images that end with '18.jpg' in the application data 'roadnavdata' folder are incorrect images. Probably 50% of the total '18.jpg' images are correct, and they are all near my initial location at the CA and NV border. I got most of the areal images in this location first then zoomed out and moved first to CA, then to UT and CO, and that is where the repeating images problem started. There should not have been any aerial photo data on the map for the new locations. As I scrolled east I could see Lake Tahoe and Walker lake being repeated about once a state. I have screen captured the problem and included some good and bad terraserver images in the attachment.
This problem happened with the pre-compiled roadnav-0.18-win32.exe, on Windows XP. I installed Roadnav, got my GPS receiver (i-Blue 757 Pro Solar GPS Bluetooth Receiver/Data Logger) to work. I then downloaded the Tiger line maps for NV, UT, CO, NY, and CA. After that I turned on the 'Aerial Photos' View, and zoomed in and out, over a period of a couple of days, to get all of the aerial maps I wanted for specific locations. The error message happened rarely, but about 10 times so far. The terraserver image 'Tile request is invalid' error message started to happened when zoomed all the way out at detail level 0, and you can see those images along the bottom of the program screen capture.