Comment 12 for bug 104863

John, thank you for having reported back.
I'm closing the bug as invalid, because it seems like something strange was going on and the php5-gd package should add its configuration snippet correctly, just like you've experienced in the end.

Also it seems like the serverguide at http://doc.ubuntu.com/ubuntu/serverguide/C/mediawiki.html has been fixed in this regard.