I wasn’t referring to any upgrade in particular, just C6 lanes in general. I’ve not had anything horrible happen to me. As far as I remember, takes just follow on lane by lane but I don’t recall doing much if any comping in between.
Just as an afterthought: when you do this comping of takes that later vanish, have you been moving events between lanes? This changes their proirity and often results in things turning up in unexpected places. I’ve found it more predictable to leave things where Cubase puts them until I’m ready to tidy up when I’ve finished the job.
6.0.3, Win7, both 64-bit, btw.