Is there a way to remove the gray line above the center post, right below the header?

Sorry, I'm very new to working with themes :-)

Gavin

what gray line, I don't see one...maybe you need to provide some more info like your versions and url

i might have stumbled on your answer (i hope i'm not stepping on any toes?) .. check in STYLE POSTS AND PAGES under POST CONTAINER.. the second default line is :

border-top: solid 4px #eee;

change the eee to fff or whatever your background colour is .. (or else i suppose you could delete the border-top bit entirely)