Quick Cart Link doesn't work on FireFox4

Hi,

My shopping site has a quick cart link button with a label called "View order".
This button works fine on Google Chrome, Safari, IE, but not on FireFox4.
It worked fine on Firefox3, now I have no clue what the problem is.

I tried adding the code of;
<?php
error_reporting(E_ALL);
ini_set('display_errors','on');
?>
from line 1, but nothing comes up when tested. So I guess there's nothing wrong with PHP (I mean, with other browsers everything works correctly anyway.)

Maybe it's some kind of CSS conflicts?
Could you help me finding out what the problem is and tell me what I can do to fix this?
Just in case I copied the code for the quick cart link button area.
If you need more source, please let me know.

Thank you for your help,
Rika


<div class="eC_Simple_Slate_Verdana eC_Simple_Slate_Verdana_QuickCart">
<form action="<?php echo ($_SERVER["PHP_SELF"].(isset($_SERVER["QUERY_STRING"])?"?".htmlentities($_SERVER["QUERY_STRING"]):""));?>" method="post">
<table width="124%" border="0" cellpadding="0" cellspacing="0" class="right_cart">
<tr>
<td class="eC_QuickCartLabel">
<img class="bag" src="rowing_images/bag.png" width="14" height="18" />
<a href="shop_cart.php"><input name="Swift_View_100" type="submit" id="Swift_View_100" onclick="MM_goToURL('plugins/parent','');" value="View order" /></a>
&nbsp;( <?php echo $Swift->TotalColumn("Quantity"); ?>&nbsp;items&nbsp;)&nbsp;&nbsp;|&nbsp;Total:&nbsp;<?php echo WA_eCart_DisplayMoney($Swift, $Swift->GrandTotal()); ?>&nbsp;&nbsp;</td>
</tr>
</table>
</form>
</div>