Same thing has happened to me about five times...told the dealer...could not duplicate, etc. I found the best way to avoid it is to turn off the cruise control when you've stopped driving...in other words, make sure it's off before you start the car, and then engage it when you need it. It's always worked from this initial condition.
Cruise control oddity?
This morning I was driving to the gym and as usual put on the cruise control to avoid a speeding ticket. After my work out, I went to use cruise control and it did not engage. I turned the main switch off and back on and it still didn't engage. Stopped, turned the whole car off and restarted. Then the cruise worked. Odd? Anyone else ever experience similar or know if this is a sign of something impending......or is it just the full moon???? 
