Servlet pathTranslated API

I want to switch from my IBM ICCS 4.2 server to Jigsaw,
 but I have troubles concerning the Servlet API.
 
All my servlets are based on the pathTranslated method of a Http-Request.
Your implementation (beta1) returns null.

If I try a trick (which works under IBM):
getServletContext().getRealPath(request.getPathInfo()),
I do not succeed because getRealPath mirros the given path.

I think that the path must be calculated starting at the root resource and
searching the given path. Is there any help??

        Yours Andreas Bufe.