Aha, found the trick!

Tue, 10 May 2005 21:35:39 CDT --- (Emacs)

Solved the problem with journal-create-entry overwriting my previous entry. All is fine so long as you publish the previous entry first with emacs-wiki-publish (C-c C-p). I really should report this to the mailing list since it causes data-loss if you don't get it right.