They use this stuff every day, yet, when something goes wrong, they can spend minutes upon minutes trying to figure out what's wrong. It happens a few times a semester at least, and it's always funny when it does.
I guess it's just a sign of age for some of these people, but other times it's something pretty obvious what the problem is, and it's funny to hear brave souls from the audience try to help the lecturer by yelling out advice.
Usually,about ten minutes into the class, someone calls the tech people and they come to fix the problem, and eventually the class reverts back to its original dullness.
Oh well, at least those glitches give us a break from the endless socratic method, and if they put off my being up in class for another 10 minutes, I won't say a word (even if I know how to fix it). Come on, neither would you!