Pretty good!
Now for the niggles!
1. Start location of map in top left of screen a bit naff. Prefer centre in screen, Maybe red highlighted tile should be middle tile as well.
2. Click on orange button to bring up menu. Click cancel. You cant paint on tiles until you change to another tile texture.
3. Been mentioned before. Your tiles just dont look right. They look like they overlap and just dont tile neatly.
4. If map is behind tile select 'window' and you keep mouse button clicked on the 'prev' tile link, it cycles back thru tiles AND changes map tile at same time BUT then crashes with some sort of image error. Suggest that when mouse is inside a gui window, disable updating of map that may be underneath.
Maybe it would be better to have a dedicated area of screen for all the selection stuff, maybe a banner across top or bottom of screen.
If your mansion house needs haunting, just call Rentaghost!