[SOLVED] Missing RSS Feed

I never even realized, but I've been with RSS feed for a while (not even sure at which version of Atahualpa the feeds stopped working since I don't really subscribe to my own feeds, but I do have a 6.4.4 installation that seems fine)

Basically the feed gets a parsing error - XMP abruptly stops after <content:encoded><![CDATA[ when the permalinks are set to /%postname%/

Changing to a different theme resolves the issue (requires dumping browser cache)

So out of the following feeds only one works:

.../feed/ (doesn't work)
.../feed/rss/ (works)
.../feed/rss2/ (doesn't work)
.../feed/rdf/ (doesn't work)
.../feed/atom/ (doesn't work)