Problems with Undo

Hi!! i´m having trouble with blender, when i undo some action, or when i hit Crtl+z, blender crashes, i have the latest version of blender (2.69) on 64 version in windows 7, if anyone could help and tell me why blender is doing this and how to solve this, would be really appreciated

Adrián Fuentes

When you undo…what actions exactly? What circumstances produce a crash for you? Or are we just supposed to guess?