After more testing I believe that if a 4gb memory card is used you will be able to run a file of 2048Mb in size. The Nav will not load a file larger than that. I don't know if it is a hardware or firmware limit on the file size but I believe it is a firmware issue. Maybe if garmin comes out with an firmware update that will read larger files. I base this on the fact that the nav reads the 4gb card.

I now have all of North America, Hawaii and a good part of Mexico on the card.

If anyone has a 4gb CF card would like to hear your results. Also meant to say I am running firmware V4.7