My cruise control works great....until I hit a bump.

With my cruise control set if I hit a bump it will usually cause it to decelerat as if I had tapped the brakes and then accelerate again. The cruise control light never goes off. If it is a good sized bump, it will disengage it completely turning the light off.

Where should I start with my troubleshooting?

Also, after 2 hrs of 75mph with cruise control then shutting down for 5 minutes, I had it not start until I opened the hood and moved the throttle. Did this only once and don't know if it is related to the above problem or not.