Try this. Open up /skins/Kubrick2evo/_main.php and find this part.

<?php if( $disp != 'single' ) {
        echo '<div id="wrapper">';
        } else {
        echo '<div id="wrapperWide">';
        } ?>

change it to

<div id="wrapper">

(Remove the if statement and the php code around it, leaving only the opening div tag.)
Then find this:

<?php if( $disp != 'single' ) {
        echo '<div id="bPosts">';
        } else {
        echo '<div id="bPostsWide">';
        } ?>

and change it to this:

<div id="bPosts">

Find this:

<?php if( $disp != 'single' ) { ?>
<div id="bSideBar">

and change it to this:

<div id="bSideBar">

Finally, find this:

<?php   } ?>

<div id="pageFooter">

and change it to this:

<div id="pageFooter">

perfect.

thx a lot!