Yes, of course these are other places to check, but the brake light thing is one of the most basic things to check...the failure of a brake light bulb will cause a fault in almost every cruise control system in modern vehicles. I'm not suggesting that ALL problems stem from this, but I have come across this situation before...in Jeep KJ, Nissan Patrol and VW Golf...was always the brake light bulb.
Anyway, I wish you good luck.