CS2 - why does my cursor change??

For some reason, sometimes when working in Photoshop CS2 (PC platform) my paintbrush cursor changes. I have it set in preferences to show the brush size and it usually stays that way, but occassionally, it reverts to precise mode so I cannot see the brush size on the screen. The only thing that seems to work is closing PS and restarting it. What a pain.

Has anybody had this problem, and if so, do you have an easy solution?

Thanks,

Lou

caps lock key toggles it.