This change fixes this issue:
This may not be the best way to solve the problem, but it currently works for me.
Modified to work with Rails 3.1rc4.
Does it continue to work on Rails 3.0.x?
I'll try to test it out tomorrow just to make sure, then I'll merge it.
Sorry, I have no idea if it still works in 3.0. I figured a pull request was the easiest way to show what worked in Rails 3.1 and then you could add whatever checks may or may not be necessary to get it working under 3.0. Since I still haven't officially launched my site I've just moved the whole thing to 3.1 and unfortunately I don't have a really easy way to test it under 3.0 anymore ( if I was a smart guy I probably would have kept a 3.0 backup ). :-)
Thanks for putting the plugin together, it's been a big help getting the plupload stuff working.
Works great on the earlier versions as well, so thanks again!