if you are having error cannot open/find map_housenumber trying to view map in a 320_240, don't panic it is a simple fix, as posted by marcy99 on *********, just copy and paste both files from 480_272: as follows:-
1. Copy data.zip from SD card to hard drive (it’s much faster to add files to zip whilst on the pc than it is on SD card)
2. Open data.zip + click on folder ui_igo9
3. Go to folder 480_272
4. Navigate to and copy and paste both map_housenumber_bg.bmp & map_housenumber_heading.bmp to desktop
5. Go to folder 320_240 add both files (from above) using add button on top of zip window
6. Replace new data.zip with one on SD card
7. Restart iGO Primo & you are done.