So. This happened last week. It was pretty obscure, so I thought worth a post.
I had a little trouble with my mouse. Here's the symptoms:
1. Clicks were not registering. I could physically tap, or press the trackpad on my macbook air, and they simply weren't having an effect. 2. Oddly, I was experiencing the exact same problem with my external trackpad.
So..what was the cause. Well here's what I tried:
1. I knew it had to be software related, and not a dodgy track pad; If it were faulty hardware one would work and another wouldn't. 2. So I reset the PRAM - No effect. 3. So I reset the NVRAM - No effect.
Except on one occasion, just after reboot, it was working ok for a short period of time.
Then Jason hit on an idea. "Disable bluetooth" he said. So I disabled bluetooth; low and behold, the track pad started working. Re-enable, instantly stopped agin.
Then...we looked at the list of connected devices: Subtely, in bold there was a device not not on my desk "Dermot's Mouse".
So began an office search. A little while later, about 10 feet away, in a box, we found my old magic mouse. Upside down, with something on top of it, causing it's button to be essentially pressed.
So. next time this happens to you. Check you list of devices. Do you know where they all are?