link_to_remote options[:position] broken in edge?

It seems that for options[:position] to work in edge rails now, you
must specify "'bottom'" instead of :bottom. Prototype is expecting a
string here, and if you feed it the symbol the javascript is written
as {insertion: bottom} which results in a javascript error.

I'm not sure what's changed to make this so. If it's something with
Rails/Prototype and not something that I changed in my app, then the
documentation for link_to_remote should reflect the change.