Mouse button 4 conflict or virus problem horrifying me.

Question

I have a mouse button 4 problem which occurred a week ago on my first Imac which I returned to the Apple Store for another Imac. However the same thing happened on the second Imac where everything including the USB extension cable was completely replaced and absolute no parts of the computers were the same. The problem happened on the two different Imacs where in the first case on the first computer expose which was assigned to the Mouse button 4 kept turning on and off by itself as I merely rolled the mouse back and forth and where in the second case on the second computer dashboard which was assigned to the Mouse button 4 kept turning on and off by itself as I again rolled the mouse back and forth. In both cases, in completely different computers, fluky things started to happen, all beginning with the same Mouse button 4 and the function assigned to it.
Today, a week later, it happened again but did not start a cycle once I clicked the Mouse button 4 again. In the other two cases, the continued appearance and disappearance of the Mouse button 4 function apparently caused the mouse to become so confused and crazy that merely by pointing at a menu item like File or Edit or View, the drop down menus came down all by themselves without pressing the left side of the mouse! In both computers, first with expose turning on and off and then with dashboard doing the same, it became very difficult to carry out the technician's instructions to click the blue apple, click system preferences, go to mouse and keyboard, etc.
I informed the technician at Apple Procare when this happened on the second new computer that the left and right mouse buttons seemed to be self-actuating and clicking by themselves without me touching them. He had me shut down the computer, unplug all wires from the USB ports including the power cord and hold down four keys at the same time while rebooting to reassign the devices to the USB card ports presumably.
The genius at the apple store told me that there was never anything wrong with either my first or second Imac and that there was some other factor responsible for the strange goings on like my two peripherals a Canon N676U scanner or my new HP laserJet 1022 printer in the way of a conflict with the mouse control especially most notably mouse button 4 actuating without pressing it at its own whim!
Up till the time that I talked to the genius, I had theories of my own. I did a virus check with two separate trial versions of anti-virus software for Mac, I erased and installed Tiger in each computer after each identical occurrence and finally even erased and installed Leopard which I bought. My theory was that my backup disks from my PC were hosting a Mac virus which I may have caught on my backup disks because a friend of mine with a Mac goes all over the web into dangerous and exotic sites. She once gave me a Trojan virus in a download of some music which apparently was hosted on her Mac and transferred over with the download of music as a strange setup.exe file.
I used the antivirus to scan all my backup disks from my PC which I introduced into both my first and second Imac. No infections.
I changed the USB extension cable, not trusting the one I got from the apple store nor did I trust the replacement one I got from them with the new machine. I used a Radio Shack cord instead which fits more snuggly.
I called Hewlett-Packaged and Canon to find out if there were any known issues of conflict between control of the mouse and the drivers of either my printer or scanner.
It seems like in both computers only the mouse button 4 was affected and by my turning it on and off, on and off, on and off, the USB card lost control of the other buttons of the mouse so that the technician had to reset each of the computers during their separate occurrences of the same exact "bug".
I went into safe mode but I don't know what that proved by shutting off the drivers of the printer and scanner. Right now I have the scanner driver and printer driver totally uninstalled and am monitoring the IMac for the odd behavior without the peripherals attached. What I don't know is if the problem if there is some conflict between my printer driver or scanner driver and the Mouse is confined to the Mouse button 4 which constipates the rest of the button by turning on and off repeatedly while rolling the mouse back and forth...or if the conflict if that is the problem really affects more buttons than just the mouse button 4 where Mouse button is the most obvious sign because it starts up expose or Dashboard (which ever program is assigned to it in the mouse and keyboard settings).
If there really is any important conflicts, if they are confined to mouse button 4, should I merely turn off that button in mouse and keyboard settings in system preferences and run dashboard and the nifty widgets from the taskbar or from mouse button 3 even, and disable the crazy mouse button 4. This will only work if the conflict or whatever it is, is confined to only mouse button 4.
I don't know yet whether the constant actuation of Mouse button 4 clogs up the use of the other buttons which apparently become self-actuating with a mind of their own, or whether the possible so-called conflict if it exists and is the cause is really affecting more than one button. What supports my belief that it is a one button problem is that I substituted a logitech mouse which doesn't even have Mouse Button 4, and the problem haunting the technician and me moments before plugging in the different mouse disappeared! Before putting in the logitech and at the height of the problem the pull down file, edit, view menus dropped down by merely pointing at the label without even pressing the left button on the mighty mouse! At this point the left clicking was self-actuating!
I either need to disable mouse button 4 so it doesn't clog the USB Card port for the mouse or use another mouse.
I need to know if my theory of an overloading of the mouse is feasible? Or must I isolate the offending printer or scanner which I am presently doing by uninstalling them all if it is really even caused by one of them would need to be replaced with a compatible new peripheral. Expensive!
If my scanner or printer is incompatible which I am not sure I know how to test for which is the real cause of the problem. If you think that my theory is right-on about Mouse button 4 clogging up the rest of the buttons then it would be better to just turn it off or use another mouse or an older Apple Mouse than uninstalling each peripheral one by one and troubleshooting until next summer. Hope to hear from you guys. I really need help. Note: every aspect of my Imac purchase during these events have been replaced and replace again. I have had 3 separate apple mighty mice, 3 USB extension cable replacements, and two Imac in the time since October 12th when it started. I have called tech support until it is coming out of my ears. Now I am relying on you all. Oh, I have erased and reinstalled every operating system twice to make sure it was not a corruption in the OS in each computer.
Sincerely,
Stephen Borisoff

Answer 1

James,
Sorry I am so lengthy. The problem is that with the technical support guy on line, when the Mouse button 4 event occurred I described to the tech that I was pushing and pulling the mouse from the back end to avoid touching the buttons on the side and every time I rolled the mouse a few inches forward the dashboard assigned to mouse button 4 appeared and next when I rolled it back the dashboard disappeared, I rolled it forward and it reappeared and so on. Then the tech wanted me to click on the apple and go into system preferences and as my cursor touched the file menu to get to the preferences that menu dropped without me left clicking the mouse. As I passed over edit and view they just dropped down.
What do you make of that? I am presently running OSX leopard without my printer and scanner installed. If I see no problem in two days, I will plug in the printer and install it. Then after that the scanner and see if the problem happens. I will follow your suggestions about relearning the mouse though.
Stephen
Stephen