here is what I did, and works perfect.
1. set the map to auto download
2. zoom in to max on the left upper corner of the region you want to download
3. go in download area and "view center" will show you the coordinates for that point.
4. do the same for the right lower corner.
5. select again "download region" and put the 2 sets of coordinates.
6. select the zoom levels.... and download.

I downloaded a BIG part of Oregon for the zoom levels from 4 to 16 (you can see all the streets and the names for the highways) in about 200 MB.
I have to study the code and maybe with help from gnuite I will make a windows app to download the maps... and then copy them on the card when you need them...

This is a great application, thanks gnuite!!