I've had the 2431 for 3 years. I may have gotten 3 hours use from it. It works fine for the first 5 or 10 minutes and that's when the volume fades. Then it returns and then it fades again and doesn't stop. Calling support was the fastest way to get the run-around that I've ever seen. No help at all but they are willing to let you call back. Still no help. I packaged and mailed it back and after many weeks was sent a brand new replacement. Same problem. I eliminated all environmental possibilities such as disconnecting other phones, computer, VCR, etc. The problem still existed. I've learned a $130 lesson 
