When I set the resolution to higher than 1024x768, I get weird black symbols 'imprinted' on the screen after world creation and after the map is moved once (zoom, scroll). It then remains this way until the game is restarted.
On game load: After zooming the camera: Moved the camera over:


Notice that the location of the imprinted pattern does not change as the map moves around.
At higher resolutions, I got more interesting patterns. The last two show the non moving pattern very well.



At 1024x768, I did notice a similiar issue. It wasn't an imprinted pattern, but an outline appeared around the edge of the map after the camera moved. (I think it was the ocean).
On load: After moving camera:


An example debug.err
dxdiag