Over the holiday weekend, Comair had to cancel over 1,000 flights because of software problems. It turns out that, as I read in the F-Secure Weblog, the flight planning software they were using was using a 16-bit counter to keep track of flight staff changes...so after 32768 changes it would simply stop working. Details are available from an article in Cincinnati Post. This is the kind of madness I was expecting for Y2K, not four years later when we're supposed to have learned that lesson by now.
(Please note, because of the time that has passed since I wrote this article, it may no longer reflect my current views or the most accurate and complete information available on this subject.)