Scrolling on hover (Windows issue?)

This is kind of a weird issue that I run into periodically, and I think it is related to windows -- but I am not absolutely certain.

Let's say that I am looking at a web page (maximized) and I need to take some notes. So I open Notepad or Wordpad (not maximized, so that I can see web page below while typing my notes on the smaller notes page.

Now, the reason this works so well is that I can scroll either the maximized web page or the small Wordpad page just by hovering my cursor over the appropriate page. This means that I don't have to toggle back and forth between the two pages and both stay open so I can see them both.

The problem is (and I cannot figure out the cause/trigger) is that sometimes, after awhile, the page I am hovering over will not scroll unless that page is actually in focus. That means that I have to toggle back and forth between the two pages. And everything I toggle to the web page, I lose the ability to see the Wordpad page until I toggle back.

I was just wondering if anyone had see this before and/or knew why this happens. Am I doing something in Windows that suddenly changes the way the hover behavior works?

Thank you very much.

Nevermind, all. I think I've found it.

I have a free utility on my computer called KatMouse. I originally installed it because EchoPro would not scroll in Windows 7.

It turns out that one of the advantages of this application is also allowing me to scroll a window that is visible but not active. Great for multi-taskers, like me.

The one thing I haven't figured out is that sometimes KatMouse stops working. Sometimes the solution is as simple as turning it off and on. But that doesn't always work.

Anyway, please disregard this question.