AJAX Uploader with Nginx, Not Catching Files

[ztaylor4]

Has anyone set up nginx to work with an AJAX uploader like this one
before? http://valums.com/ajax-upload/

Passing the upload through to my Tornado server works fine, but I want
nginx to handle the file before it gets that far.  I have nginx set up
to intercept regular file posts from our pre-AJAX page with
"upload_pass" and "upload_store," but now with the file in the body of
an XHR request, nginx doesn't treat it as a file for things like
"upload_store."

Also, my AJAX page gets back a 415 error when trying to send the file. 
I'm using the script for image uploads if that makes a difference.

I was thinking I might be able to save a log of the request as the image
file, but that seems like too much of a hack.

Any help appreciated,
Zach

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,226657,226657#msg-226657