Since installing CS6MS several weeks ago, I've been required to enter my serial number at least a half dozen times. I don't know why I keep getting asked for it.
I have a MacBook Pro with Bootcamp, and half the time I run Win7 under Parallels, half native boot into Win7, if that matters. It doesn't matter to any other companys' suites of software but whatever.
Any idea what gives?
Well each time you switch between native and virtual the software probably needs to revalidate its licensing because Adobe defines virtual platforms as separate machines...
Are you running your CS6 anywhere else? If so, that would make three systems in total and would explain having to reauthenticate your switched copy each time on the dual-boot computer.