While adding a google groups link to the wiki, I noticed the section
numbers seem to be out of sync, e.g if I clicked on the final edit link
on the page, it brought up an empty section, I had to click on the
penultimate edit link in order to edit the final section.

Seems likely some content in the "7 Ballast Types" or "7.1 Switchstart"
entry has upset the wiki software.

http://wiki.diyfaq.org.uk/index.php?...#Ballast_Types