I posed the first comment in this thread over a year ago and despite others noting that they have the same issue, the problem has never been resolved. I may have an answer.
The issue was that the left panel in the Library Module would not scroll unless the cursor was clicked onto the elevator bar. Thumbwheel scrolling over the folders did nothing.
Today I was working in the Collection top-level folder and I noticed that scrolling worked fine. Moving up to main photo folder,
Disk (F) on my machine, I found that the scroll wheel would not work. That's odd, I thought. Scrolling works in the Collections folder, but not in
Disk F folder. There's got to be a fix for that! There is.
If you expand the folder using the arrow on the right side, the folder will not scroll. If you close the folder and re-open it by clicking on the bar, not the arrow, it will scroll. However, if you open another top-level folder, the scrolling will cease to work until you close the folder you want to scroll and reopen it by clicking on the bar again. It's kind of goofy, but at least it is easier than grabbing the elevator bar every time you need to search through a lot of subfolders. And, I think this proves that the issue is not my mouse driver as some have suggested.