No blank line after informalequation

Hello,

I use informalequations to markup mathematical equations like this:

    <informalequation>
           <mediaobject>
             <textobject>
               <para>1 + 2 + 3 + ... + n = 1/2 * n * (n+1)</para>
             </textobject>
           </mediaobject>
         </informalequation>

In HTML output, there is a blank line before *and* after the equation, 
separating it nicely from the flow of text around it.

In PDF output, there is only a blank line *before* the equation.

I am using stylesheets 1.62.4.

Greetings,
Joachim

-- 
Joachim Ziegler                       Stuhlsatzenhausweg 85
Max-Planck-Institut für Informatik    66123 Saarbrücken, Germany
Email:           Tel.: (+49) 0681 9325-127