Admin CP -> Styles & Templates -> Style Manager -> Edit Templates -> BB Code Layout Templates -> bbcode_code
REPLACE the contents of bbcode_code with:
Code:
<div style="margin:20px; margin-top:5px">
<div class="smallfont" style="margin-bottom:2px"><strong>$vbphrase[code]:</strong></div>
<pre class="alt2" style="background-color: #FFFFFF; margin:0px; padding:$stylevar[cellpadding]px; border:1px dashed #000000; width:$stylevar[codeblockwidth]; height:{$blockheight}px; overflow:auto"><div dir="ltr" style="text-align:left;">$code</div></pre>
</div>