I know there's a handful of us who have been experiencing this issue, so I thought I'd create this thread for us to post our responses/solutions from VZW.
My story: VERY early Incredible adopter, preordered. Ran 2.1 for a long time, rooted for wireless tether, left everything else stock. Got impatient, tried one of the early leaked OTAs, no sound from ear peice, went back to stock 2.1. Waited some more, got impatient again, upgraded via RUU. Same problem, went back to stock. Within 20 minutes of going back to stock from RUU, got the official notice from VZW (finally!), upgraded OTA, rebooted, SAME PROBLEM. At least now I thought I could call VZW for support direct. After 30 minutes on the phone doing nothing special, tech came back and said only solution is to replace it, replacement now on the way.
I'm really hoping that some of you out there with the same issue will get a different response. It definitely seems software related, as it works fine with 2.1, but every iteration of 2.2 I've tried disables it or otherwise prevents it from working.
For those of you with this issue, when did you first get your Incredible?
thanks all