The spell check feature of Firefox is not working on this forum. I'm using Firefox 9.0.1 on Vista-64 bit. The spell check on this machine works on other web forums using Firefox. Firefox options>Advanced>"Check my spelling as I type" is turned on.
The reply to post boxes on our site are programmed in a similar way to that of say the search box on Bing.com. The Firefox spell-check doesn't work on that site either for example. I will look into this for the future however.