Firefox cannot click to change windows, and other mouse? issues

Cannot always use the mouse to click between different windows of Firefox, unless I alt-tab first. The problem resumes shortly later. I cannot resize the windows either, or minimize/close/anything, those icons do not light up. I can still scroll and otherwise do anything within the active window.
Cannot use the mouse to select text in a drop down list in Firefox.
Dragging icons on my desktop fails to move them, either to a different part of the screen or into a folder icon or open folder window.
I have run one full system scan with Avast, but it found nothing.
The only two things I did recently was grab an old mouse to use the mousewheel and it updated the driver, and I have two mice on at once.
I just pulled out the other mouse and am using my Logitech marble trackball mouse, the driver of which I just updated.
Also, I went to a website and made two downloads, Masseffectsaves.com.

This is not a problem about which I recall seeing any traffic, so the following link, which is usually the best advice for starting to diagnose and solve Firefox problems may not be applicable. Nonetheless, I advise you to start with this information, which may assist you:

Standard diagnostic - Firefox - MozillaZine Knowledge Base