OAuth token out-of-date screen not served as text/html

When I went to authorise a JAC gadget on Extranet, I was redirected to the following URL:

http://jira.atlassian.com/plugins/servlet/oauth/authorize?oauth_callback=http%3A%2F%2Foauth.gmodules.com%2Fgadgets%2Foauthcallback&oauth_token=4zXLpR7MPgMlK8RR7IRjp36MWnDBRvso

This comes back as text in the browser. See the attached file for the source. The page content is:

The request token you are trying to authorize is not valid. Please try another token.

I'm currently logged into JAC, with remember-me active. The response headers are as follows:

Date: Mon, 30 Aug 2010 05:30:20 GMT
Server: Apache-Coyote/1.1
WWW-Authenticate: OAuth realm="http%3A%2F%2Fjira.atlassian.com" OAuth realm="http%3A%2F%2Fjira.atlassian.com", oauth_problem="token_rejected"
Content-Length: 3560
Connection: close
Content-Type: text/plain; charset=UTF-8

The content-type here should be set to text/html, not text/plain.