I'm seeing this same bug. Supposedly it could be caused by older versions of libxml2, but I'm using version 2.4.19, which is quite new. I've hunted around the mailing list archives, recompiled from scratch, etc. but I still wasn't able to fix it.
The only thing that worked was Giles Turner's workaround, which was, as he mentioned previously, to change the header of each index.docbook file from V1.1 to V1.0. This fix worked like a charm, because I was able compile kdebase, kdenetwork, etc. with no trouble after making the change. I hope the doc team can commit the workaround, because I'd hate to have to make the changes on my copy every time I update from CVS. (There are around 30 such changes needed in kdebase alone.) Trevor (Complete bug history is available at http://bugs.kde.org/db/41/41374.html)
