I just test ran some of your feeds, and while I get a couple of badly formed tags, I don't get anything as near as bad as what I'm seeing on your site. Have you tried re-uploading the php files that handle feeds. (I forget the relevant files, but I'm sure they're listed here somewhere.)
no, but would you know what those file(s) would be? is one of them functions_wysywig.php?
not sure even what to search on to find those files.
--------------- Added [DATE]1222901620[/DATE] at [TIME]1222901620[/TIME] ---------------
also - it looks like the < and > items in the feed are not parsing correctly... this not happening = weird issues once it writes the feed