Error updating to 2.1 - usb serial port cannot open

I've gotten successfully to the portion of starting the update.  I installed the drivers just fine, went through, get to the update portion, and then get this error message:

e - dll cannot open the usb serial port.  code 87

I'm on Vista.  I've installed the drivers as an Admin.  I'm running the exe as an Admin.  I've uninstalled and reinstalled 3 times.  I've pulled the battery, put it back in and started the update repeatedly, switched USB ports and done it all again.  What am I missing that could be causing the update to always throw this error message? 

Any help would be greatly appreciated.  Thank you.

Try this:
http://en.kioskea.net/forum/affich-192383-can-t-open-my-usb