I tried to grab all the older podcasts from iTunes yesterday, and many of them are giving 404 and 403 errors. Something odd happens though; if I try and download all of them, some will download, some will say "Done," even though they haven't downloaded, and some will generate errors. Then when I try to download all the remaining episodes, a couple might download, and this happens from time to time. So the errors are most likely on the server side; perhaps there are too many connections? In any case, whoever manages the podcast should have a look. Feel free to contact me for more info.