I am using PS CS. My tools that use a brush (ex. clone stamp,
burn/dodge, eraser) don't work. Other tools that don't use a brush
(ex.
crop, move, gradient) work fine. When I try to use a tool that uses a
brush, I see the tool step documented in the history log, but there is
no effect on my pixels! This problem exists on layered and nonlayered
files and on the background layer. I have tried everything, including
deleting my preferences.

What have I done? Can anyone help me? My work is paralyzed.

Thanks.

Mfamo