Beacon Battery's intermittent

I had a unusual experience with my beacon the other day, and thought I would pass it along.  A friend and I went on a ski and had not put on our beacons until we were ready to move into Avalanche terrain. I turned on my beacon and it did not turn on, I had used the beacon just the day before and was surprised that it did not work. I always carry a spare set of battery's so I got them out and replaced the set that was in my beacon. The beacon still did not work, I figured there was something wrong with the device. I rolled it up and put it in my pack, skied the run, when I got back to the car, I dug out the beacon and it worked.  I should have had a good look at the beacon, but did not.  The next day I went on a short ski and put on my beacon, turned it on, nothing.  I continued with the tour, with the beacon on(not working) and at some point I noticed the LED was flashing, it was now working. When I got home I set about trying to figure out what was happening.  I started with the battery's, checking the contacts, and the contacts in the beacon, I discovered that one of the beacon contacts was contaminated with the adhesive from the duck tape I use to store battery's in my pack. A quick clean with alcohol and my problem was solved.