Problems! I've used my Logitech Optical Mouse Model M-BJ58 for several years now without any trouble in combination with Logitech Control Center, 2.1.4 (214) being the last version I've used, so I didn't think long after seeing that version 2.3.1 (231) was out, and updated to 231. It ruined my afternoon. I spent a few hours recovering from the troubles that 231 caused me. First, 231 insisted that my device (mouse) have at least one button to which is assigned the right click function. Darn. I don't want a right click. My mouse has a left button, a right button and a clickable scroll button. For years I've been happy with the click lock function assigned to the right button, but 231 doesn't let me do that unless the right click function is assigned to, e.g., the scroll wheel click. Worse yet, it removed the existing click lock function from the right button and assigned the right button function to the right button. It also removed the sound control I had assigned to the scroll wheel, and I got that back only after reverting to 214. User beware.