Last modified: 2011-09-15 15:18:34 UTC
Please set $wgRestrictDisplayTitle to false on English Wikibooks. http://en.wikibooks.org/wiki/Wikibooks:Reading_room/Proposals#Set_.24wgRestrictDisplayTitle_to_false
Done
I'm sorry, it doesn't appear that arbitrary titles are being allowed. Using {{DISPLAYTITLE:foo}} works for "Foo", but it's not possible to use {{DISPLAYTITLE:Bar}} for "Foo". Real example; this edit produced no title change: http://en.wikibooks.org/w/index.php?title=Wikijunior:Introduction_to_Mathematics&diff=2168561&oldid=1939577
The setting was set to true in the config file, where it should have been set to false ;)
Fixed.