[xsl] Problem getting margin-top to be zero

[Asbjørn Thorsen <a.r.thorsen@xxxxxxxxxxx>]

I need to tell xsl-fo exactly how big/small margin-top is going to be. 
In the case I am working with now I need to set it to zero. The problem 
however is that when I use FOP to generate ps-format I can't seem to get 
a top margin less than 21mm. How can I get a smaller top margin? The 
printer I'm using is able to print anywhere on the paper.

Asbjxrn