In my experience the cords on the G9 and G9x aren't great, and they tend to start fraying where it connects into the mouse. That might be the cause of your issue. IIRC, it has a 3 year warranty so there's a good chance you'll be able to get a replacement.
Aside from the cord, the G9x is pretty much my favorite mouse (gaming and otherwise) ever. I bought a spare the other day since it looks like it's being phased out.
Good call on the warranty I looked up my order it was actually 2 years and about to lapse on the 3rd year this Wednesday. For once I was hoping for an Indian support center but I'll have to submit the claim tomorrow. Appreciate the insight /repped.