Ok, I finally got around to assembling my dongle. Everything went very smoothly and when I got done, I followed the driver link and installed the VCP 2.06.00 driver, dated 3 November 2009. Plugged it into the USB port, the PC found it, and set it up. Vixen sees the new COM3 port.
But then I picked up my printed copy of the wiki dongle instructions and it says to install version CDM 2.04.16. Huh? I found the CDM version, but is it required? That version is no longer on the FTDI link page - you have to follow the wiki link to get it. I think I may need to back out the driver and re-load the documented one.
I won't have a DMX device until tomorrow evening, at the earliest, to test - but should I worry about the driver and just install the 2.04.16 version or just wait and test. Is VCP 2.06.00 and updated version of CDM 2.04.16? I think it is and it will work as the comm port appeared and vixen sees it.
But...
Thanks everyone for sharing your wisdom....