... to cancel the UBI download or can I just ignore the messages that it's ready for download? I was led to understand that there's no charge until it's downloaded but the DVD arrived from Amazon around the same time as UBI's notification arrived by email.

CoD's running great so far BTW. A few noticeable glitches but then IL-2 FB had its growing pains too so by comparison this one has great potential IMHO. It automatically set itself up for 3 displays which was a pleasant surprise.