Single quotation marks v. double: no definitive answer yet

All of you who chimed in on this question in my earlier entry should definitely read the posts I received. I'm not sure where to begin in that the responses look so radically different from each other. Some Brits say the single quotes drive them nuts -- that they're wrong, wrong, wrong -- while some say they're right. teenygozer suggests the possibility they're Australian while pointing out an X-Files/Highlander crossover fic proving they exist beyond HP fandom. koimistress provides textual evidence of their use in 1930s Brit lit. It's a fascinating debate. Thanks for all of your contributions.

Go read each other! Share the fun. :)