DOCBOOK-APPS: Headheight inf Jadetex/FancyHdr

I don't understand what is happening with the TopMargin and HeaderMargin
of the Docbook stylesheets. The latests versions of Jadetex/Fancyhdr seem
to assume that the headerheight is a fixed value. I thought it should be
derived from the HeaderMargin and TopMargin paramaters.

As a result, a warning message appears when you have something in the header
that doesn't fit in the headheight of Jadetex. And then, the rest of your
document is down scrolled.

Any help?

Thanks and regards,

Juan R. Migoya
TEAM S.L.