Hi all, seems there's a bit of an issue with the Blogger architecture with regards posting comments. Sometimes when you click "comment" at the bottom of a post the text box appears, but there is nothing available in the 'choose profile' drop-down. Make like a geek and turn it off and turn it on again (go back and then hit 'comment' again). This does in fact seem to fix it.
google, really. pfft.
needs some jelly bean.