Template is missing, latest edge

hi everyone, I have a project that is using a good snapshot of edge, however I tried some latest rails builds and I got some weird errors.

when using a respond_to block in a controller, rails isn't able to find the related view. this is a pastie, with a backtrace and controller code: http://pastie.org/474696 (please note that I'm using a namespaced controller here).

I would really like to understand what's going on. thanks.