OK so not strictly Sonar related, but we all (or most of us anyway) use mice to operate our DAW's and the erroneous double click issue with Logitech mice can drive you stark raving mad when you're working on a project. It's a known issue. I replaced my last one without researching the issue (just put it down to wear) but when my relatively new one developed the same problem I figured I'd Google it. Turns out it's a static build up in the capacitors and the solution is very easy: 
 
Plug the Unifying receiver into a different USB port and follow this procedure:
 
1. Shut off the mouse and remove the batteries.
2. Press all the buttons repeatedly for 30 seconds. This will drain all the static energy that may be trapped in the mouse.
3. Put the batteries back in the mouse and turn it on.
4. Wait a few seconds for it to re-connect and test the buttons.
 
It worked like a charm on my mouse...I'm clicking away in Sonar like a beast without any fear of those annoying freaking double click snafu's. 
 
 

I'll have to look into that. I use their laser mouse - last one got flaky after about two years, had to replace it with another one. Man, that damn thing would double and triple register clicks...
 
It's still laying around somewhere - maybe I'll test your solution to see if it'll do as a backup.
 
Also using a Logitech solar-charged wireless keyboard.. 'look Ma, no batteries'!
 

What logitech software are you using, if it's from the CD have you downloaded the latest version of the bloatware? ;)
Or better still if possible try and get it running without logitech keyboard and mouse software running (if possible).

I never install mouse bloatware anymore. Never had anything but headaches with it. They work just fine without it. 
 
The double click thing is apparently static buildup. I know it sounds like a bit of an unlikely solution but come to think of it I've experienced a similar thing before years ago, with a Compaq laptop. The thing would slow down to a crawl every few weeks for no apparent reason. Eventually I called support, and the tech guy told me that it had to do with a build up of static. He told me to unplug everything from the laptop and hold down the power button for 2 minutes. It worked like a charm. The computer worked perfectly after that, and I had to do it every couple of months. Everyone I told thought I was joking and insisted that nothing like that could slow a computer down. But, I saw it with my own eyes. 

SuperG
I'll have to look into that. I use their laser mouse - last one got flaky after about two years, had to replace it with another one. Man, that damn thing would double and triple register clicks...
 
It's still laying around somewhere - maybe I'll test your solution to see if it'll do as a backup.
 
Also using a Logitech solar-charged wireless keyboard.. 'look Ma, no batteries'!
 

 
I have the exact same keyboard. Best one I ever owned. I love the feel of the keys and the solar charging feature is fantastic. The only thing is, I found that after 18 months or so it wouldn't charge so well. I ended up getting a new one, but I didn't mind at all. 
 

sharke

SuperG
I'll have to look into that. I use their laser mouse - last one got flaky after about two years, had to replace it with another one. Man, that damn thing would double and triple register clicks...
 
It's still laying around somewhere - maybe I'll test your solution to see if it'll do as a backup.
 
Also using a Logitech solar-charged wireless keyboard.. 'look Ma, no batteries'!
 

 
I have the exact same keyboard. Best one I ever owned. I love the feel of the keys and the solar charging feature is fantastic. The only thing is, I found that after 18 months or so it wouldn't charge so well. I ended up getting a new one, but I didn't mind at all. 
 

It's possible to replace the battery - it's just a major PITA - plus it's a very specific battery - can't just pop in your everyday coin cell.

SuperG

sharke

SuperG
I'll have to look into that. I use their laser mouse - last one got flaky after about two years, had to replace it with another one. Man, that damn thing would double and triple register clicks...
 
It's still laying around somewhere - maybe I'll test your solution to see if it'll do as a backup.
 
Also using a Logitech solar-charged wireless keyboard.. 'look Ma, no batteries'!
 

 
I have the exact same keyboard. Best one I ever owned. I love the feel of the keys and the solar charging feature is fantastic. The only thing is, I found that after 18 months or so it wouldn't charge so well. I ended up getting a new one, but I didn't mind at all. 
 

It's possible to replace the battery - it's just a major PITA - plus it's a very specific battery - can't just pop in your everyday coin cell.

Yeah think I'll skip that...don't think I could even get the thing open anyway 

I don't remember how old my Solar Keyboard was when the battery lost its mojo, but I think it was after 18 months. I called tech support and they sent me a new battery for free. Very nice of them! Then I spent a few hours replacing it. That battery door thing has a BAAAAAAD design! But the keyboard is excellent!
 
I had this problem with double clicks twice. Once because I had two receivers pluged into the computer and both registered the mouse clicks. The other time I had this, I don't know what was wrong. But the idea of static is interesting. It could have been that. Actually, that makes sense if I think about it.