Domain mapping with 'www'

Hi all!

I have released many single Wordpress sites for the company I work for this year. All this sites are ranking good in Google. We chose to let every domain begin with 'www'.

We are migrating all these sites to Wordpress MU now, because - as you know - it's far more efficient to have just one Wordpress installation and plugin database for every site. And Wordpress MU works superb. However, we've experienced one problem with the mapping of all domains to the Wordpress blogs.

We use the MU-plugin 'Domain mapping', to make sure that the domain name 'www.domain.com' points to the right part of Wordpress MU. However, this plugin strips 'www' from the domain name. This is something that is documented in the plugin also: "www" does not count because it will be removed from the domain name.

For SEO purposes, we don't want to strip the 'www' part of the domain name; we want to keep it! What can we do to make it so?

Thanks in advance!

Jeroen.