Oh, thank you, you saved my head and my weekend! It worked great. By the way, it’s

#primary article.hentry .wp-post-image {
	width: 100%;
}

more than enough for solving, i do roughly understand what is the following for

#main-nav {
	margin-left: 0;
}
#masthead,
#content {
	overflow: hidden;
}
#primary article.hentry a {
	display: block;
	margin: 0 -30px;
}

but is starts another problem of putting submenu items under the main content, but it’s just an optional feedback if you didn’t know.

Thanks again, the theme is great and i do really like it.

Regards!