Index generation for PDF broken?

Hello,

I tried to create an PDF out of an article containing some indexterms.
The HTML version contains an Index, but the PDF fails to generate one,
even if I explicitly set generate.index to "1". I use the recent
docbook-xsl stylesheets to create the .fo file and fop 0.20.5 to create
the PDF file.

Can anyone reproduce this issue?

Regards, Daniel