Cruise Control problems of the 2004 Mazda Tribute

I was driving on a freeway (4 lane - 65 mph speed limit) on the afternoon of 2/3/2007 with my cruise control set to 65 mph. I noticed that I was speeding up, and within a short time, my speed had climbed to about 90 mph. At first, I thought this was a malfunction of my speed control, but after touching the brake and turning the speed control off, it continued to go about 90 mph. At this time, I noticed an exit coming up in about 1 mile - so I kept touching the break to keep the speed about 75-80 and when I approached the exit, shut off the car and coasted to the top of the ramp. With the car safely stopped, I was able to get the car towed to a service station, where the mechanic pulled off the air filter assembly going into what I think is a throttle chamber and found a large piece of ice holding either the choke or throttle causing the problem. It is important to note that the temperatures that day were very cold - about 10 degrees f. Below zero. After removing the ice and cleaning out the chamber with silicon, and allowing it to warm up for about 15 minutes - everything was okay. I should note that I had taken the vehicle into the local Mazda dealer about a month earlier because I noticed the throttle was sticking - they serviced it and it seemed to be okay, until the incident on 2/3/07. When I called the Mazda dealership, they told me that there was a safety recall on the throttle assembly, but they showed this part had been replaced already. I am concerned that ice can build up in this area and the same thing will happen again, whenever it is cold out. I haven't seen another similar complaint, but thought it would be a good idea to document this - this could have easily caused a major accident.