that´s my problem: if i open or create a new 3D part or assembly (doesn't matter if it's saved of not) and then i open another part (doesn't matter if its part of the assembly or not, even a new document) (while the first one it's still open) and close it (again, doesn't matter if i modify the second piece, or just close it) the design window seems to be painted for a 1 year old kid with a black crayon, the interesting part is that if i rotate the model/assembly the window camo back to normality until i stop rotating it, when i stop rotating it the windows seems to be painted again. I don't know if it's a problem with solidworks and windows 8.1 or between soldiworks and my laptop because I've installed SW 2011 and SW 2012 and the problem is the same in both, as a reference i have an HP Pavilion with windows 8.1, processor AMD A10 with AMD Radeon graphics.
PD. The problem doesn't occure if i modify the piece directly in the assembly as long as i don´t save it.
There's a screenshot of the problem, the first one show up the problem, the second one what happens when i rotate the piece (it´s like nothing had happened)
Hope you guys can help me, at least to figure out whats the source of the problem is.