Видимо, пришла пора добавить docbook-4.3. Scrollkeeper обломался на документации в Гнумерик-1.3.93 $ grep DOCTYPE gnumeric.xml <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
Fixed in docbook-dtds-4.3-alt1