Hi chaps ... I have been using P/shop for years, never had a problem, I'm on a mac using CS4, today when I pick the brush I get the eye dropper cursor when the cursor is hovering over the image (mouse up), it paints when I left click, as normal - very strange. I'm sure I've checked everything - reset and deleted prefs, repaired permissions and restarted ... I can, of course, reinstall but have never done it before and have heard (having googled the problem) about odd problems reinstalling like the need to de-register etc, so any advice as to a solution to the cursor problem or advice on the best way of reinstalling photoshop I'd be most grateful.
Run cocktail often. Or, leave your computer on 24/7 so the OSX scripts that start in the early morning can run automatically and clean stuff up. I repair permissions through disk utility often to help prevent issues.