The RSS blocks for various forums & glossary are showing changed URLs as illustrated in the following example on upgrade from 1.9.5+ to 2.0 latest weekly:
http://examplemoodlesite.com/mod/forum/discuss.php?d=2013&parent=5688
http://examplemoodlesite.com/mod/forum/discuss.php?d=2013&parent=5688
Because of the ampersand issue in the URL, all URLs are broken.
This is true for internal feeds. There is no URL change issue noticed for external feeds.