Thanks to Matthias Brstle for his t=1 implementation
and lots of support.

Thanks to John P. Looney for testing and comments.

Thanks to Roland Dirlewanger <rd@dr15.cnrs.fr> for testing,
and information on other product ids.

laurent <lpi@dobs.com> reported a bug.

Thanks to Nelson Escravana <nelson@escravana.net> for endless
debugging.
