John,

No, I am not using MS BT Software.  My Fujitsu 4121 was not already BT equipped, so I bought a Zoom 4312 PC Card.  This card uses Widcomm Inc S/W supplied by Zoom on CD.  The version is 1.4.2.12.  In places this is listed as 1.4.2 Build 12.  This is still the most recent version on the Zoom web site.

Tom Thibault