cured?

[B@fink]

Ok.....so i have replaced my ignition coil unit (6cyl engine coil is 1 unit for the whole car) after it had a bad habit of dropping 2 cyls at motorway speeds (did it twice quite unexpectedly) which has restored my happiness and confidence in the car, but, and this is the bit i can't figure out....my cruise control which has been a bit hit and miss of late, working intermittently and usually only at motorway speeds after trying to get it to turn on several times (checked the vac system and control unit, seem to be all ok) is now absolutely perfect. Works first time everytime at any speed i want, when i want, how i want! As far as i know there is no direct link between the systems, but the evidence is inescapable, it was mostly a gonner and is now just like it always used to be. Anyone want to hazard a guess? (i'm going for rogue voltage type interference)