It's a fairly common problem. I thought there was a fix for it that was more firmware or software related? My brother and friend had the same problem with their Naga's. In any case, if cleaning it or fixing the mechanics is what you want to do, a quick google search on the issue (which happens to auto fill) will get you some videos and other tutorials on how to do it.
As snide as Poofighta's reply was, given my brother and my friend's experience, along with the commonality of the issue, I would be inclined to agree. I myself own the Cyborg MMO7 (2 of them actually), as well as the Logitech G600, and both of served me quite well. I prefer the Cyborg because of the button layout as well as the ergonomics. The Logitech has a layout much like the Naga though, if you're already used to it, while at the same time having an intuitive feel to the buttons (as in to not get lost hunting for the right button). It also has a more superior shift button than the MMO7 (which basically doubles the buttons you have).
And regarding your warranty, if I'm not mistaken, the latest version of the Naga isn't even 2 years old yet. You could also prove validity for a warranty based on the serial number, should your product have one. I used to work tech support for HP (well, an outsourcer) about 10 years ago. We would always verify warranty by serials numbers, and never even bother with a receipt. In either case, it doesn't hurt to try. Asking is free.