I've been using a Plantronics 640 for several months now along with MS Voice Command and have had no real issues. Today suddenly it starts acting odd when I am trying to tell it to dial a number directly "Dial 713-XXX-4664" . After some experimenting I realize its basically unable to recognize the number "6". MSVC will either replace it with "8" or just act like its not there and give me some real weird interpretation of what it thinks its hearing. It seems to be having a problem with syballant sounds especially.

I've performed several soft resets. I also reloaded MSVC and confirmed that the problem is with the bluetooth headset (MSVC works fine when I use the phone's mic).

I had been trying some of the volume hacks posted in the forum but had reset them back to their original volumes. Anyone had anything similar happen?

As I recall, this is a known issue. Bluetooth audio uses a lower sampling rate than Voice command requires to have consistent recognition.

Yea, but it wasn't having this problem until the last day or 2 (and I've been using it with teh BT headset for 2 months). While I would have some problems with getting a Contact name correct sometimes, it was usually dead-on when it came to dialing by speaking the phone number. Now, its not only inaccurate, but its doing things like only repeating back 6 or 7 numbers when I gave it a full 10-digit number.

I've had problems with inaccuracy over BT--especially with any kind of background noise (car). But, if you say it worked perfectly before, then maybe your headset is the culprit. Try a different one.