Hmm, I suspect the version of aspell that comes with Debian stable does work. Here's from my error.log
[14/Nov/2003:15:37:09][31404.1024][-main-] Warning: Gettings dicts and default_lang for aspell failed with error message: "Error: Unknown Action: dump dicts"
[14/Nov/2003:15:37:09][31404.1024][-main-] Notice: You might want to upgrade to a more recent version of Aspell ... http://aspell.sourceforge.net/
So I need to upgrade, I think. That might explain why spell checking doesn't work for me. I see the spell-checking drop down boxes, but after I submit the form, don't get a spell-checking page.