Firefox Xforms extension

I still can't get it to work

I installed Firefox 1.5 (on Gentoo/amd64) + XForms extension, but it 
doesn't seem to work as expected.
When I try the examples at http://www.mozilla.org/projects/xforms/
the pages just render as they did before I installed the Xforms 
extension. Is there something else I need to do to activate it? Any hints ?
Do the developers from the Mozilla Xforms project read this e-mail group ?

Thanks again,

Nico.