I've been having problems commenting on other's blogs. Finally, I got tired of it because I see some really great posts that I would love to comment on, but always get this error saying I don't have permission.
I went to Blogger's help area and saw that there is a problem with commenting on posts when the comment section is embedded underneath the post. For some reason though, if you have a pop-up comment form, there is no problem.
I'm asking everyone that sees this, to please change their comment options to the pop-up comment style, so that we can post comments. I know I cannot possibly be the only one with this problem!!