How weird, I hear you ask?

Well, my 10-month old daughter is now able to reach up to the desk and pull things down, and this week she discovered my mouse.  I wasn't too bothered - after all, how much damage can she do to the mouse?  It's pretty robust, and was still going strong after about 8 years of solid use.

Last night, though, I discovered that the wheel was sticking and sticky.  It looked like some gooey substance was coating the rubber track on the wheel.  I tried to clean it off, but it seemed to just rub the rubber off and it felt like it was making the wheel stick when I moved it.  I googled for a potential cleaning suggestion, and it sounded like others had problems with the rubber making the wheel stick, and suggested cutting the rubber off.  I did this, and it solved the sticking problem - the wheel now moves freely.

However, when I turned it back on and turned my computer on, weird stuff started happening.  The left click, for instance, would work if I clicked on the start button (running Windows 8.1), or if I clicked on an icon in the taksbar, but when that program opened, left clicking inside the window would make it lose focus.  In some parts of the window, a left click would work, in others it wouldn't.  For instance, in Chrome I could click to open a new tab, but I couldn't click and select the URL.  Other weird stuff - right-clicking a tab would close it; the wheel (middle button) wouldn't click or work, and it didn't scroll, though I suspected it might be related to the absence of the rubber track, so I put that to one side.  It was doing my head in, so I abandoned it for the night and went to bed.

I woke up this morning to have another crack at it.  Now, the left and right click doesn't work at all. I've tried it in a different computer, and it has the same problem.  But weirder still is that when I plug the USB receiver for the mouse into the computer, it interferes with the other input devices.  For instance, on my Surface Pro 3, once I plug in the mouse receiver, the trackpad and the touchscreen no longer work, even after I unplug the receiver - I have to hard-reset the Surface to get the trackpad/touchscreen to work again.

I haven't googled it yet, basically because I have no idea what to search on.  It's a weird and convoluted problem, so I'm hoping someone on GZ might have an idea.  Worst case scenario is I'd replace the mouse (and keep it out of reach of little children - though I doubt she is the cause of all of these problems), but I'd like to salvage this great little mouse if I can.

Any ideas?