Wanted to make an update to this topic, because I have figured out how to fix my mouse. My center scroll button click functions are back!
So after 3 pages of suggestions and a consensus that I should just replace the mouse, I've put in my order. Of course, I figure this out the day after I place my order. sheesh.
Then, my cursor started moving erratically so I did a search on why that might be happening. So I blew the dust out of the optical opening and the mouse is now working just fine. I also cleaned a very dirty mousepad and that may help as well, but I've tried functions and I can now open links with the center click, open tabs from the tab drop downs and even discovered that I have a scroll left or right function by bending the scroll wheel left or right that I never knew I had before.
So the word is, if your wireless mouse is not working right, try cleaning it before you go through all the other machinations listed in this topic.