I just purchased a new m575s track ball mouse. I have several of logitech trackball mice on a number of my computers. I would like to use the "wheel" that is at the index finger location for zooming in and out but I cannot find any setting adjustments for this in the "logi" software. As older logitech mice wear out I replace them with new. In previous versions of the trackball configuration software I was able to adjust the function of every button and wheel, I am unable to do this on this new m575S that arrived yesterday. This is VERY disappointing. I would have expected your configuration software to get better and more useful over time, not worse and less useful. ?maybe its time for you people to clean house and hire competent software engineers.