Game Engine keeps crashing.

I’ve got a very simple scene up, only a block with a plane (Each with a texture). When I try to run it, with Blender Materials, Blender crashes. I get a message like:
Memoryblock Uiblock: end corrupt

How do I fix this? Also, I’ve seen people say that Blender can make screensavers in the game engine, is this true? Cause that’s what I’m trying to make.

Edit: It crashes without Blender Materials too.