The work-around is to use the upgrade-cd to install a non-activated version of Vista (faster), and then perform an inplace upgrade (cleaner):
- Boot using the Vista Install DVD.
- Click Install Now and do not enter a Product Key when prompted and uncheck Automatically activate Windows when I'm online.
- Pick the proper product edition (Home Basic, Home Premium, Business, or Ultimate) when prompted and install Vista.
- After the install has completed, then launch the Vista install again, but do it from within the newly installed Windows Vista.
- Select to perform an Upgrade and now enter the Product Key when prompted.