I'm curious but what did the verizon tech do in your initial post that alleviated the problem? What drjunky9
mentioned earlier about being auto-provisioned to a lower speed could have happened to combat some unexpected noise. I'm more curious to see what your stats would look like if the dslam set your speed back above 3000.
Not to mention your attenuation is already quite high at the lower speed setting indicating that perhaps you have a decent amount of signal loss somewhere that could potentially be out of your control (like a noisy pair at the pole outside for example).
Edit: credited wrong user :P whoops.--