As of 10.0.5, when I move the cursor over the map, it doesn't select the correct things. For example, when zooming the map out to Azeroth, I can only select and zoom into the continents on the left because the selection area associated with the cursor is offset way to the left (if that makes sense).

I have scaling enabled (155%), fwiw.

Confirmed. Both Tomtom and Bliz' own map markers place the icons at an offset that is no doubt some multiple of how much you had the map scaled up by Mapster. I hope this is fixable, as the normal map behavior sucks.

This is fixed in the latest update. This also means that scaling is available to everyone again without taint issues.