It's thankfully a rare affliction, but over the years, I've heard of many cases. For speakers and presenters, Presentationitis is a terrible condition that could be described this way: you test your microphones, projector, software and hardware - probably multiple times - and then right before the presentation (seminar or class) is about to start something goes wrong. It's happened to me a few times, it's happened to Scott Kelby, and I'm sure it's happened to many other speakers.
Last Friday in LA I had another case. Two hours before the seminar we were testing audio and it was great. Then we turned a microphone back on and had a buzz that just would not go away. We changed mics, batteries, cables, you name it and still no fix. So the decision was made to bring in a different sound system. Cool - at least we discovered this before the day started.
Then we tested my laptop, connected it to the projector... all good. I'm such a worry wart that I even disconnected and reconnected several times to make sure it worked fine each time. In part I did this because of a rare but known problem that can occur when you have a Wacom tablet connected and then connect to a projector. After multiple tests, everything was a go.
Fast forward to moments before the seminar was to begin and we switched the cable from one laptop to mine and...nothing. Black screen with no sign of life. The laptop did not refresh, the video connection was not made, nothing. Disconnect the tablet? Nothing. Force a restart? Nothing. Panic a little? Yes. After several minutes of trying everything and imploring my laptop to work, it finally did, Phew. Except for one thing: when I moved my pen on the tablet, it jumped around the screen like crazy. Oh, my tablet isn't configured probably - no problem, I'll just pop into the settings and fix it. Nope.
So, I taught the first two classes using the trackpad on my laptop. Now, I'm pretty good with my trackpad, but it was definitely a challenge. Hopefully, it was not obvious to the class (I only mentioned my problem after I fixed it at lunch time).
Why am I telling you all this? So that the next time you're watching a presenter struggle with some kind of technical difficulty, you'll realize that they probably tested everything, but were hit with a sudden unexpected case of Presentationitis.
(Thanks to all the wonderful people who came to my seminar Friday - I had a blast, despite the glitches)
[EDIT: Here's a quick summary and some great pics from Alan Hess. Thanks Alan!]