I have not tried it yet, because i don't have access to euro dvd. I'm moving back to poland (from US) in few months, and I want to bring my 450h aboard. I would be very upset if I won't be able to use Nav... Anyways, you can always buy the unit for euro model, and swap it. I'll bet you it would work...
I will continue to hunt down the euro dvd here in US, so I can test it out. I will keep you updated... ;)