Back your brake switch out a bit. Cruise control will cancel if you hit the brakes. The brake switch is a double switch 2 wires for the lights and 2 for the cruise. the cruise side is very sensitive.

Or test you cruise set button you can download manuals at hondatech.info . It could also be a lot of other crap like a cut wire. Down load the etm (electrical trouble shooting manual) flit to cruise control thy have a system description.