What’s Up With Firefox’s Spell Check?

I’ve blogged about the Firefox spell check before, but this really got metoday: Firefox 3.0.5, the US English version with the Canadian English dictionary installed, generated this series of red error lines:

firefox-spell-check-sucks

Do you see any spelling errors in that sentence? I don’t. So what’s with all the red lines? Come on Firefox developers, you can do better than this…