First, try switching browsers. I write the blog on Google Chrome, and Blogger/Blogspot is a Google platform, soooo... I've heard that switches between IE, Firefox and Chrome can conquer the comment box.
Second, if all else fails, e-mail me at chemjobber -at- gmail/dot/com and I will be happy to help, or if all else fails, I will post your comments myself. Seriously.
Last, has anyone ever tried to comment and figured out how to solve their troubles? If you can, leave a comment (yes, ironic.)