Chrysler Repair: Cruse Control, imposable, cruise control

Question
Everything works great on my 99 Town & Country, except one thing.  Whenever I set my cruse control, on a flat long road, the speed would go one mile per hour in either direction.  Meaning if it’s set on 60 mph.  You can see the speed odometer go from 59 to 61.  It’s not doing this rapidly, but very softly, but you can tell it’s doing it.  Can you help?

Answer
its normal  its imposable for it to stay right at 60 road conditions and other stuff take affect. On the other hand u could also have a small vac leak either at the cruise control servo or the lines going to it and the vac chamber that holds vac for the system.