Wired USB Magic Mouse moves but does not click

I am working on an Mid 2011 27" iMac running OS X 10.8.5 (current updates installed). I'm on my 3rd magic mouse in about six months. This is a very peculiar phenomenon, in that, my magic mouse (USB wired) has stopped having the ability to click. It will move and open the dock and even applications from the dock, but that's about it.

Strangely enough, when I move this mouse to another 27" iMac running the same OS, etc. the mouse works as it should. Fortunately, I am in charge of the equipment at my small company and can just keep exchanging mouses. The "new" to my computer mouse will work on my iMac fine.

I have zapped my PRAM, unplugged the computer, tried other USB ports, etc, to no avail. If I was not fortunate enough to be able to switch out mouses, I would be at the end of my rope considering if I purchased two new mouses in the last six months I would not be happy. Like I said, the mouses that were previously on my iMac work on identical work stations but not on my iMac. I've tried plugging the older mouses back in on my iMac months later and they still won't work correctly. Anyone else experience this?

I've also noticed that my screen has a wavy, light pattern (looks like ghosting, but not from any document considering the shape of the lighter pattern - looks like smoke rising on the left side of my screen) that will disappear after a short time. Could these be related? Failing Logic board? Video card? Any incite would help, before I lug it into the Apple Store.