Multipart forms "bad content body"

I made a note of this in another ticket (http://rails.lighthouseapp.com/p..., but it might be a slighty different issue.

Here is the error output: http://gist.github.com/77057

When input.read(boundary_size) is called it looks like it clears the buffer so when the next read gets called the buffer returns nil.

I'm really stuck on this one. I would appreciate any help.