Map displays incorrect data. Maps appear as fragmented tiles When I zoom in beyond a certain level, the map appears in square tiles. Some of these tiles are correct, and others are not. The roads and landmarks appear correctly in Google Maps, but the topography layer looks pretty randomly filled in. In another app called Mapdroid, the incorrect tiles appear to be repeats of correct tiles. 

This occurs on both my Digno ISW11K and Casio IS11CA (firmware version 2.3.3). I first noticed the problem (for both phones) when I was recharging via my car's cigarette lighter while refreshing map data.

I'd be totally happy if I could just somehow reset all the map data. . .

Does anybody else have this problem? Thanks for any help/ideas.
try clearing the appdata and cache. still if your problem isnt solved try unstalling the updates you have done to the app.
you can do all this by goin to the settings then application manager select the app and do whats mentioned above