Mongrel big trouble with --prefix and rendering

Hi folks,

I have got a big problem out here.
I’m using a mongrel cluster with --prefix parameter, but something very
strange it’s happening;
rails redirection happens without troubles, and I’m redirected to the
right page, BUT! if I try to render a page from my controller (i.e.
render :action => ‘begin’ ), all that I receive back from the browser is
a “page not found” error, because it points to wrong url, missing the
needed prefix.
for instance, the url of a normal web page looks like:
http://www.example.com/example-site/action1
If I try render :action=>‘begin’ I get back:
http://www.example.com/begin
completely without the example-site prefix.

I’ve tried googling and searching on the argument but, seems impossible
to find something realted to my problem.

Any suggestion will be appreciated.

Thanks in advance

Stefano