Niels Christian

Just to note that using

$attachment_id

instead of

$thumb_id

, did not work for me. But using

$thumb = wp_get_attachment_image_src( $thumb_id, 'large' );

as silverandrew was suggesting did work on line 1158.

This might help

https://codex.www.ads-software.com/Function_Reference/wp_get_attachment_image_src

Havent tried it out yet though.

also found it on line 1156:

if ( function_exists('has_post_thumbnail') && has_post_thumbnail() ) {
			$thumb_id = get_post_thumbnail_id();
			$thumb = wp_get_attachment_image_src( $thumb_id, 'full' );

yes, well check your style.css, look for

#l_sidebar {
	float: left;
	width: 203px;
	margin: 40px 0px 0px 0px;
	padding: 0px 19px 20px 19px;
<strong>	border-left: 1px solid #E2DDDE;</strong>
	font:11px/18px Verdana, Arial, Helvetica, sans-serif;
	}

my bold, this is the line making the borders.

or check the css style for the right side bar (#r_sidebar)

the code should be pretty straight forward, explaining a lot.

@grizzarkhov
Is it in this one you changed the margin and padding

#l_sidebar {
	float: left;
	width: 203px;
	margin: 40px 0px 0px 0px;
	padding: 0px 19px 20px 19px;
	border-left: 1px solid #E2DDDE;
	font:11px/18px Verdana, Arial, Helvetica, sans-serif;
	}

?
@maxbux
I believe you move this line

<?php include(TEMPLATEPATH."/l_sidebar.php");?>

in both home.php and index.php into a newly created div tag above the contentleft div tag