Don't want to be editing core WP Files

I am having issue with a mobile theme plugin that seems for some reason to be adding my sites domain in twice to certain icons.

The homepage is okay but all other icons appear with a src value like

src=”//www.mysite.com//www.mysite.com/wp-content/blah/blah/image.jpg”

I have tried posting to the WPTouch forum but had no reply about it.

So at the moment I am having to do a replace in the core wp-includes/nav-menu-template.php function so that it looks for duplicate domains and replaces them.

It’s not a generic regex as I don’t really need one plus I don’t want to change it (like I will at the moment) with every WP update e.g

$nav_menu = apply_filters( ‘wp_nav_menu’, $nav_menu, $args );

if(preg_match(‘@src=\”(https?:)?\/\/www\.mysite\.com\/\/www\.mysite\.com@i’,$nav_menu))
{
$nav_menu = preg_replace(“@src=\”(https?:)?\/\/www\.mysite\.com\/\/www\.mysite\.com@i”,”src=\”//www.mysite.com”,$nav_menu);
}

if ( $args->echo )
echo $nav_menu;
else
return $nav_menu;

If there is a better way to stop image URLS like

src=”//www.mysite.com//www.mysite.com/wp-content/blah/blah/image.jpg”

and just having this

src=”//www.mysite.com/wp-content/blah/blah/image.jpg”

Then I would like to know thanks!

Rob