I have the latest version of the software (7.4.2). I recently tuned an '07 classic 3500 LBZ truck, and when I went into the speedo calculator to adjust for the 22" aftermarket wheels and tires, it did not change the parameters in the tune when I hit apply. I had to manually type in the new value from the speedo calculator. I thought this was an issue with the previous version, and fixed now. (???)