getting strange results with the BB code parser

[RossOliver]

Hey,

I've altered my includes/functions_bbcodeparser.php file to add an image after every hyperlink (as the mediaWiki software does for external links; see my wiki );

	if ($type == 'url')
	{
		// standard URL hyperlink
		return "<a href=\"$rightlink\" target=\"_blank\">$text</a> <img src=\"./images/misc/ext_link.png\">";
	}
	else
	{
		// email hyperlink (mailto:)
		if (is_valid_email($rightlink))
		{
			return "<a href=\"mailto:$rightlink\">$text</a> <img src=\"./images/misc/ext_link.png\">";
		}
		else
		{
			// not a valid email - don't link it
			return "<span title=\"$rightlink\">$text</span>";
		}
	}

The problem is it seems to be converting the <img src=""> tags into bb code tags somewhere and I'm struggling to find where. Basically; if you add a link to your post, then preview it, it will add the tags into your post. If you press preview again it will add another set - one for every time you preview/submit the post.

Any ideas where it's doing this?

Thanks for your time,

-Ross