Upon opening mails from Gnus' summary buffer, emacs complains about "gnus-article-add-button: Invalid byte code in /usr/share/emacs/22.2/lisp/wid-edit.elc" causing mails to not load completely, i.e. display in the article buffer remains raw. To reproduce start Gnus from emacs-22.2-5.fc9.x86_64, connect to any news/mail server and open an arbitrary mail. wid-edit.elc checksums from a fresh emacs-common download and my installed version are identical: (sha1) 808545e835a6008dd0ab8443dca79e0c63bc0653 /usr/share/emacs/22.2/lisp/wid-edit.elc I'm using emacs in terminal mode (--no-window-system).
I cannot reproduce the bug myself anymore, so I'm closing it.