Tried v27.1 with just the modified vehicle icons, but I still get the same incorrect CD/DVD inserted error message when I try to update the nav computer. Thus, I'm stumped.

The only ideas I have left are:

1) Changing the CD-R type (I'm using Memorex and buring them at the lowest speed setting).

2) Something's wrong with NavTweak 2.2 program. Maybe I'll try going back to version 1 and see what happens.

3) Something's wrong with the vehicle icon graphics. I'm using Windows paint to save them as PNG files. However, I don't know if they're in a "PNG-24" format or not???

Also, I have the background color set to plain white (255, 255, 255). Is that the color it needs to be for the transparency?

Other than that, I just dunno. Any help would be appreciated.