I'm not sure what you've been reading but I suspect they are pulling your leg. No DofE that I've encountered (and I worked for many years at a leading clematis wholesale grower) had any scent at all nor is it listed as fragrant in clematis source I am aware of.

Hi gardengal,

I'm not joking.
That's why I had to ask, to make sure.

Here are my sources:

Helpmefind says strongly scented.

Here is the link to a nursery. They pretend the same thing:
http://www.goodnessgrows.com/id260.html

And finally Roy Genders in his Scented Flora of the World

"The only variety, which has been given the fragrance of C. fortunei..."

So, what do you think?

Here is a link that might be useful: Duchess of Edinburgh - Helpme find

Mine isn't. Sorry.

Again, none that I have encountered have had any sort of noticeable fragrance.

Thanks Gardengal & Opelia :)