I have enjoyed reading your latest report about your Namibia workshop. I am writing this topic because I have faced a similar experience with a 1 series camera shutter release button. In January 2005 I was camping in the Empty Quarter desert, in Oman. I have shot extensively with my trusty EOS 1V for the first day of the trip. Then, on the second day, I noticed that the shutter release button was not working.
Actually, it would require two presses to fire. Fortunately, the camera would work fine using the timer. Because I was using a tripod, it was not a big problem. Again, there was sand blowing around. Back in town, I send the camera for a clean-up and all was fine. It was the only time that the 1V has failed on me.
I am glad you enjoyed Namibia, I have never been there, but I am fascinated by deserts. There is also a good report on Namibia in the latest Travel Photographer’s Network website.