Your logo IMAGE is VERY LARGE... 1,761px × 891px
... and it is then being FORCED into the LOGO WRAPPER to assume a size of 58 pixels high, by your site width (mainWrapper) of 969 pixels.
Here's the evidence in the CSS:
PHP Code:
#logoWrapper{
background-color: #ffffff;
height: 58px;
}
#logo {
padding: 0.6em 0 0 0;
}
PHP Code:
#mainWrapper {
background-color: #FFFFFF;
text-align: left;
vertical-align: top;
width: 969px;
}
So what you are doing is FORCING a re-size of a very large logo (1,761 X 891) into a space that is much smaller and shallower (969 X 58).
The NEXT most important consideration is that after the image has been forcibly re-sized by your CSS, the ASPECT RATIO has changed too.
1,761 X 891 is (given a few decimal places) an ASPECT RATIO of 2 : 1
969 X 58 is (given a few decimal places) an ASPECT RATIO of 17 : 1
If I take your WHOLE LOGO as it currently stands (1,761 X 891) and reduce it to a height of 58 pixels AND maintain the aspect ratio, the WIDTH should be 114 pixels.
But this just makes your logo look FAR TOO SMALL and indistinct.
BEST SOLUTION is to RE-DESIGN your header logo from scratch, making it SHALLOWER and WIDER.
---------------------------------------------
AH IGNORE WHAT I SAY ABOVE ... I see the real culprit...
Some idiot called ANISH has decided to OVERWRITE CORE BEHAVIOUR on the template and FORCE the header into his own HARD-CODED HTML
HTML Code:
<!-- ANISH
<div id="logoWrapper">
<div id="logo"><a href="http://pamperedpetz.com.au/"><img src="includes/templates/black_pure_free/images/logo.gif" alt="Designed by 12leaves.com - ecommerce templates design services" title=" Designed by 12leaves.com - ecommerce templates design services " width="177" height="90" /></a></div>
</div>
<div class="clearBoth"></div>
ANISH-->
<div id="logoWrapper" style="width:944px;height:200px;overflow:hidden">
<div style="width:943px;height:180px;overflow:hidden;margin-top:-10px;padding-top:0px;padding-bottom:2px;">
<img src="http://pamperedpetz.com.au/images/logo.jpg" border="0" height="200" width="960" />
</div>
<!-- ANISH -->
Fire Anish... he does not know zencart, or how to construct proper logo headers for this template.
Ask him for a refund before you fire him.