Being new to mobile developing, I was pleased at the ease of
development with asp.net using the mobile controls.  First app worked
like a charm, until someone with a Samsung E715 tried it.  You get a
very generic "Not Found" error.  What should I be doing in the event
of an unknown device?  Is there a default type of page that is
rendered (wml,xhtml)?

further notes: the samsung phone uses WAP 2.0; the page I am trying to
load is a reentry page that loads correctly the first pass, but on the
second pass when query string variables would be present, is when it
errors; there is no authentication being used.