I have been running Alpha2 for a while with no problems.
Last Sunday I loaded 2.5Beta and every thing still functions OK but I am getting what looks like the edges of a window in the upper right quadrant of my model windows. Like a transparent window is in the corner and all you see is the left and bottom edges of the window frame. It happens the same in each model window and does not change size with the model.
I am running WIndows7 64bit with a ATI Radeon 5700 Video Card
Anyone else seen this?