As the subject says, I've been having problem for a week or so where left clicking in finder (and others) if I click on a file, it double clicks instead.. so I click on a zip to select it, it goes and it unzips. I click a mp4, and it opens Quicktime, that sort of thing. I've swapped out mice to no effect. I've set the Double-click speed all the way to slow. I've done the restart and permissions fix. In days of old, I'd delete the preference file and try that, but I'm not really sure how to do that these days...anyone help?