I figured this was a bug with the 777 aircraft, but I see similar behavior in both the stock 747 and Cessna that shipped with X-Plane (both of those I tested loading in KSEA as a start point). On the 777, the click continues to be registered the entire time, so if I'm trying to change the A/P heading from 310 to 300, it gets 'stuck' and the heading display keeps turning until the click stops being registered (and the heading ends up around 120 or so). The application doesn't seem to become unresponsive-everything else within the sim continues without issue. The 'click' stays held by the system until that 1-8 seconds passes, and then it resumes like normal. But if I left-click and hold the same knob, after about a second the pointer becomes non-responsive for anywhere from 1-8 seconds. If I left-click a knob-say the AP heading set knob-it moves the knob one notch as expected. I've been enjoying X-Plane since I bought it a couple of weeks ago, but there's an annoying little problem I'm seeing, and since I bought the 777 this weekend, it's become more prominent.