Basemap is ok and it's worldwide as its name states, may be your disappearing map has been made with Mapsource and not with Mapinstall,or hasnt been properly unlocked , hard to understand what may be wrong.
Hint: use original locked .img and unlock by yourself,or better, download original map pc install unlock and use Mapinstall to load it in gps.
Btw ,can you post in map thread or in already existing threads? Hard to discover what are you talking about.
We try to keep our forum tidy and organized, opening threads for every single question, doesn't help
Every section has sticky indexes for fast and easy usage.