Level editor looks pixelated and freezes

[Finzy]

When I try to open the level editor it looks like this:



(It also flickers so much it hurts the eyes, won't see it in the picture though)

And when I try to close it by closing it normally, it just freezes. Any ideas?

System specs:

AMD A8 3500M 1.5 Ghz Quad Core
8 GB RAM
AMD Radeon HD 6740G2 1 GB (6620G + 6650M Crossfire), Catalyst 12.6 drivers
Windows 7 64 bit

Tried with and without crossfire and setting leveleditor.exe to run in high performance mode to no avail.

Steam version Amnesia with tools installed to the main game directory. The game itself works fine without any problems.

EDIT: Managed to fix it!

Fiddled around with the settings some more and set leveleditor.exe to run in low performance mode (the 6620G card) and that seemed to do the trick, it looks normal now. Seems like it has problems with switchable graphics. However I can run Amnesia itself with the dedicated card (6650M) and in high performance mode thanks to the new AMD drivers so what gives? It's still not an optimal solution as I lose fps.