I have the same exact issue, and I use it for work which is especially frustrating. I only got maybe 8 months out of it and now some of the buttons don’t function at all. I used to use a logitech mouse before and it worked pretty well, I only replaced it because I got a new razer keyboard and I wanted my macros to work together between mouse and  keyboard, can’t believe I spent almost 3 times the amount of the logitech mouse only for it to fail after a few months. I am looking into getting the piece replaced, but no luck. I am afraid I might be stuck with shoveling out more cash for a mouse  that has one small inoperable part that can easily be replaced.

Same problem here. My first two Nagas had issues with the cable. I switched to Logitech by then, and just two years ago, I tried the Naga Pro with interchangeable sides. However, the buttons stop working when I'm playing WoW. The temporary solution is to unplug and plug it again. I'm considering moving back to Logitech or trying another brand

I have the same issue. 2 of my side buttons will just stop. I used them when flying and helo will just fall out of the sky. Customer service is a joke. they keep emailing me back. I wanted to talk to someone on the phone. They said I could buy a new one online and send this on back and IF THEY DEAM FAULTY I will get my money back. I have tried air, contact cleaner, even added lifters because I thought my finger was not pushing on the button right. So as you can see I will not be able to return it as now I have tampered with it. I did this after failed email solutions.
I have own 
2 Wieve Orbiters
3 Tataus’s 
key board
and this is my First mouse. Naga pro v2
I will not be buying Razer products anymore, Nice to see Corsair hash a wireless 12 button mouse now for a lot less.

I hope that someone in management reads this makes some changes or they will lose a lot of customers.