My husband has a different computer, but it has the same behaviour.
My system:
xp SP3
calibre 0.7.49
Colour Nook sw v 1.0.1
My computer recognizes the device, but it took me some tries to get it to do so. I wonder why? Now, Calibre has recognized the device also.
I will have to do some more troubleshooting and report back.
Thanks for your quick replies.