Firefox loading raw HTML, instead of rendering the page as designed.

Using Rails 2.0.2, I have built a simple web app. Every time I use
Firefox to load any page for that web app, it is extremely slow, and
according to the log files, it completes the specified action in the
controller, but what is shows in the browser, is just raw HTML. If I
refresh the page, it loads properly. Using Safari and IE, I have not
seen the problem, but other user's of my web app are having the same
problem with Firefox only.

Has anyone else seen this problem? I thought maybe the webserver is
too slow or small to handle my simple ruby app, but since I am only
seeing the problem in firefox, I am not convinced. Any other
thoughts? Thanks in advance!

Actually ... here is more information .... This is appended to the top
of the raw HTML:

Loaded suite dispatch.cgi
Started

Finished in 0.000234 seconds.

0 tests, 0 assertions, 0 failures, 0 errors
HTTP/1.1 304 Not Modified
Server: Apache/2.2.6 (Unix) mod_ssl/2.2.6 OpenSSL/0.9.8g DAV/2
mod_auth_passthrough/2.1 mod_bwlimited/1.4 FrontPage/5.0.2.2635
Connection: Keep-Alive
Keep-Alive: timeout=15, max=99
ETag: "3ed38808c3c19b71b0747d7a47ed5a2d"
Cache-Control: private, max-age=0, must-revalidate

Loaded suite dispatch.cgi
Started

Finished in 0.000134 seconds.

0 tests, 0 assertions, 0 failures, 0 errors

..... then my raw HTML is dumped here .....

Maybe it is fixable via a config setting in my app or on the web
server? Happens ONLY in Firefox and ONLY when the server is running
slow, it seems anyway. A refresh to the page renders properly.

Thanks!!

I am using the file_column plugin, and this seemed to be producing the
message. I fixed it by opening the file vendor/plugin/file_.../
init.rb and removing the line require "test_case".