Vista IPSEC and NAT

We have a lot of IPSEC tunnel clients with Windows XP behind NAT
working fine (home offices, cell phone clients, ...). Tests with
Vista
SP1 are showing that build-in IPSEC / NAT doesn't work any longer
(without NAT it still does).

I found the solution http://support.microsoft.com/kb/944335/en-us
saying that it is by design.

Compared to XP this is an unacceptable regression, Vista claims it
supports RFC 3947 and doesn't? Is there a registry key to enable the
well known behaviour?


Daniel