WordPress MU

I recently installed Wordpress MU (2.7) and have it up and running.

When I use the TinyMCE spellcheck on a post it responds with "No Misspellings Found" even when there are misspellings.

I have not edited any of the files that came with the install, so I believe it should be using Google to check the spelling.

I'm trying to get this to work for English, although I don't think it works for other languages in my install either.

Some notes: Installed on Linux; SSL required; Viewed with current versions of Firefox and Safari on a Mac

It's not MU, it hardly works in regualr WP as well. :) I think you have to add some things to the server.

I know it's tough to get working.

Thanks andrea_r. I hope it's okay to re-post my question there then.

Just don't say you're using MU. :)

@irifkin: Try this change, it's not the same problem - but it might work:
http://blog.clearskys.net/2008/11/20/wordpress-spellcheck-woes/

@cafespain Thanks for the link, but unfortunately that didn't seem to solve it for me.

FWIW spellcheck does work if I edit the spellchecker config and change it from GoogleSpell to PSpellShell. But why doesn't GoogleSpell work, especially if it's the default?