For me Craig. Just AD2 and audio tracks, no VV. I've used Melodyne numerous times in other projects for pitch correction and timing, with no problems. Even doing entire tracks. Not a single crash.
But in my present projects, only doing timing adjustments, and only using the melodic algorithm. It simply will not work without crashing, unless I do say 5 second clips only, and bounce to clip, save, and then proceed to the next 5 second clip. Even then, the occasional crash.
As someone else said. It's like it creeps up on you, then "pow, you had your turn my friend, move along"...