I think dareino is talking here about the mouse cursor changing shape and consequently freezing the system.
This could have something to do with the video card and its drivers. If you knew the make and model of your card, you could do better web searches about the problem.
Is it happening only in your web browser or in some other applications as well? Do you perhaps use Mozilla or Firefox? Mozillas have some GUI tricks of their own. The version of the browser could be buggy. Most browsers and some file managers are based on Mozilla; they may or may not have the same problem.
These are just some thoughts, nothing definite. Searching the bug databases could help: