Go to this File:
ow_system_plugins\base\views\components\user_avatar_widget.html
Replace the Javascript like this:
{if $owner}
{literal}
<script language="javascript" type="text/javascript">
$(function(){
$("#avatar-console").hover(
function(){
$("#avatar-change").fadeIn("fast");
},
function(){
$("#avatar-change").fadeOut("fast");
}
);
$("#avatar-console").click(function() {
{/literal}
var url = '{$avatar}';
{literal}
url = url.replace(/avatar_big/, "avatar_original");
document.location = url;
});
});
</script>
{/literal}
{/if}
Its not perfect, but the script does what you want :D Full size Image.