The problem is the code tries to put the whole article into the feed, which chokes a lot of browsers and feed servers. Someone on this list devised their own RSS page with just what they wanted. I hacked the code in includes/QueryPage.php/feedItemDesc(), to be this:
if( isset( $row->text ) ) { $text = "<p>" . htmlspecialchars( wfMsg( "summary" ) ) . ": " . $text . "</p>\n"; }
In other words, I cut off the row->text part of the string. That seems to have helped a lot. You may want to search the archives for the more elegant solution.
Michelle