Hello,
According to
this article on
Russell Beatie's web site, the RSS feed is specifically for podcasting. I'm not sure why this would make a difference, though, but I'm not very familiar with SONY's PSP.
You might want to take a look at
Mioplanet's
MioMediaBox or
RSS Newsreader for the PSP and see if those better meet your needs.
Regards,
Aryeh Goretsky