Redmine

I have Redmine set up behind an Apache reverse proxy. When I try to upload files to my test project from the files tab nothing happens. I can get to the new files page and browse for the file name, but when I press the "Add" button nothing happens. From what I can tell (using Wireshark), it's not even sending a message.

I can attach a file to a document, and those upload normally. It's only when I try to upload as a file that things break.

If I don't go through the proxy and try to upload a file things work fine, so I know that the proxy is breaking something but I don't know what. I've tried comparing the html from the page that goes through the proxy vs. the page that doesn't, but I can't see any differences that look like they should cause this problem. (The java script is identical in both cases.)

The sequence I've been using when testing this is: Sign In -> My Page -> Projects -> test project -> files -> New file -> browse for file -> press "Add" button.

I am using the "bitnami-redmine-1.3.1-1-windows-installer" distribution of Redmine. Software versions:
- Redmine 1.3.1
- Apache 2.2.22
- ImageMagick 6.5.6-8-Q8
- MySQL 5.0.83
- Subversion 1.7.1
- Ruby 1.8.7-p334-i386-mingw32
- Rails 2.3.14
- RubyGems 1.6.2

All of the Redmine settings are the default for that distribution.

The Apache is the "httpd-2.2.22-win32-x86-openssl-0.9.8t" distribution with mod_proxy_html (mod_proxy_html-3.1.2-win32).

The relevant section from the reverse proxy's httpd.conf is:

ProxyPass /redmine/ http://192.168.133.5/
ProxyPassReverse /redmine/ http://192.168.133.5/

<Location /redmine/>
ProxyHTMLEnable On
ProxyHTMLDoctype XHTML Legacy
ProxyHTMLURLMap / /redmine/
ProxyHTMLURLMap http://192.168.133.5/ /redmine/
</Location>

I have attached the full httpd.conf of the reverse proxy for anyone who needs to see it.

The file new_Proxy_Legacy is the html file that comes out of the reverse proxy.
The file new_NoProxy is the html file that comes when I connect to Redmine directly.