RSS Feed Full-Text Cut-Off in Firefox

When using Firefox 3.6.18, and clicking on the RSS feed icon in the address bar for my site home page, the RSS Feed page shows posts but the text is cut off at 40 words with a “Continue Reading ->” link at the end of the post entry. I have checked in Firefox options and settings and cannot find a setting or option that is relevant to this issue.

In Internet Explorer 8.0.76, the full text of each post IS showing in the RSS feed, so IE shows the feed correctly.

I am using WP 3.1.3. I have the full-text set for RSS feeds (obviously because full-text is showing in IE).

I created a clean install of WP 3.1.3 just to be sure that none of my plugin’s or themes were the cause of the problem. With this clean install and no additions of any kind and using the default twenty-ten theme, the problem still exists.

Here is the test site URL: https://www.testrss.flam2000.com

In researching this problem I found OLD posts about this same problem in 2.x versions of WP. But I have found nothing about this regarding WP 3.1.3.

Any help is appreciated.