Notice: get_settings is deprecated since version 2.1! Use get_option() instead. in /home1/victorz9/public_html/wp-includes/functions.php on line 3382
That is a surprising error message. It points to a file which is part of WP. But in the wp-includes/functions.php of the current WP version (3.2.1) is no call of function get_settings. I thinks that maybe the last WP upgrade was not complete.
I also tried replacing our current podpress installation to version 8.8.
That is nothing you can do without editing some entries in the data base of your blog. Because this:
The XML becomes valid, but does not reflect any of our podcasts. Also, the display_podcast tag doesn't work.
happens if you do anyway.
And when I upgrade to 188.8.131.52 again ...
Please, upgrade to 184.108.40.206. .11 had a bug which may not be related to this XML problem which you have mentioned but it solves definitely a different and serious problem.
Please, post the error messages which the feed validator (e.g. http://validator.w3.org/feed) gives you.
I have validated your RSS feed again some minutes ago and all looked fine. What is your current setup? (WP version? podPress version?)