Well, the good and responsive folks from the Harmony Support Team helped me out. Here is what they said:

"I have found the problem! It is *not* a hardware problem! The symptom you are seeing is caused by the fact that you have *3* title activities in your configuration. And so, each time you scroll down, it takes you to the same, identical, title page. And so it gives the appearance of the scroll wheel skipping. To fix this, click 'My Activities', 'Delete an activity' and then delete the two additional title activities.

Sorry for the confusion/frustration this has caused you - we will try and work out a way of preventing this in future.

The Harmony Support Team."

A few days back I was checking out the add a new activity menu and clicked on title to see what it would do and, at the time, I didn't think it did anything, but I ended up adding two new title pages. So my advice: Don't do that!

Brian