Allowing alternate protocols to be entered in link fields

I would like to configure SharePoint 2007 to allow alternate protocols / links to be entered in a number of placed:

Hyperlink fields
Rich text editor (highlight text and create a hyperlink)
etc.

An example protocol would be notes:// (for Domino databases).  I've also heard people having issues with using onenote:// and mms:// but haven't confirmed this.

Here's a discussion on this topic that seems to be going down the right path:

http://www.eggheadcafe.com/software/aspnet/29711508/how-to-insert-notes-li.aspx

However, I've been unable to configure SharePoint to accept the new protocols.  It continues to give errors like:

Hyperlinks must begin with http://, https://, mailto:, news:, ftp://, file://, or \\.  Check the address and try again. (when trying to create a link in the rich text editor)

or

Invalid URL: notes://server/mydb.nsf (when typed into a URL list field)

Any help would be appreciated.

Thanks.