This is certainly a neophyte question. I tried to post a comment on a friend's BlogSpot.com site using my WordPress ID (which is an option). But when I enter it, the validation on BlogSpot transfers me to WordPress.com and says "You do not own that identity."
At first it told me I had to log into WordPress. I've done that. Now I get the "you don't own..." message.
What am I doing incorrectly?