Hi,
I was having this same problem and think I may have figured out how to fix it. I have just tried the below code on my store and it appears to be working fine (haven't noticed any problems with it yet). Give it a try and see how you go.
<a class="VertMenuItems" href="{$href|amp}"
{if $onclick ne ''} onclick="{$onclick}"{/if}
{if $title ne ''} title="{$title|escape}"{/if}
{if $target ne ''} target="{$target}"{/if}>
<img src="PUTYOURIMAGEURLHERE">
</a>