I got tired of changing batteries in my wireless mouse, so I just tried my trusty old MX 400 with OSX 10.7 and discovered that the left button double-click will not open files! I can left click and it will select the directory that I want, but once I find a file I want to open, it won't! I have to right click on it, then select "open." The settings in the Logitech Center don't seem to help--any suggestions? Thanks.