The behaviour I was seeing seems similar. The fixes are to do with various URLs used internally for redirects which are can get malformed under certain configurations of WordPress. As a result during the redirect sequence you’re not actuallly pulling from the RSS feed. Hence it is blank.
If you have access to the apache or IIS log file on your server you should be able to see the URL sequence at the tail of the log. If you post these I will have a look for you.
I’m not yet sure if I’m going to use the plugin in the site but If Martin is happy to incorporate fixes, I will do a bit more fiddling around and send more patches. The code is fairly easy to work with. I’m also interested in some of Max’s enhancements.