Disclaimer: this has happened only once since I got my Clarity in early May. Sunday, I had just gotten on the freeway, moderate traffic, but nothing right in front of me. I got up to speed, 67, 68 mph and hit the Set button on the cruise control. The CC speed indicator said 48(!). What? Kidding right? Let off the accelerator and the car started slowing. Cancel, get back up to speed, try again. Same thing. Again, nothing in front of me (for quite a while.) The fix was to hit the Main button to turn everything off and then once again to turn it all back on. It's worked fine since.