My cruise control "runs away" every now and again, usually when I hit "resume" from a lower speed after I've been forced to break. It just keeps building speed past the point where it had previously been set. This happens pretty infrequently, and when I hit "cancel" and then reset at the desired speed, it stays there. I'm surprised this would break the bowden cable or anything else - it's just the usual c.c. speed buildup, which isn't sudden at all. If it gets worse (more frequent) I'll replace the c.c. amp eventually, but the frequency hasn't increased over the 11,000 miles I've owned the car, so I'm not too worried about it.