Hi, I'm having some problems rendering some graphical elements in the Firefox mobile browser (the only mobile browser I've tested this on). In firefox and chrome desktop browsers, the arrow elements look and work just fine, but in the mobile browser, I just see the alt text values.

Here are the elements:
HTML Code:
<div class="voteContainer">

	<a onclick="selected('img/arrow_up_selected.png', 1, 111)" >
		<div class="arrowContainer">
			<img id="arrow_up_111" class="arrow" src="img/arrow_up.png" alt="Up vote" />
		</div>
	</a>

	<a onclick="selected('img/arrow_down_selected.png', -1, 111)" >
		<div class="arrowContainer">	
			<img id="arrow_down_111" class="arrow" src="img/arrow_down.png" alt="Down vote" />
		</div>
	</a>

</div>
Source: http://leke.dyndns.org/sod/index3.php

Any advice? Thanks