[Admin]

Add a check in getpostbit() that checks, if the user is using an avatar from your stock, the site of the image, then $imageinfo[3] in the <img> tag.

Because I'm nice (read: bored ), find this in functions.php:

		if ($post[avatarid]!=0) {
			$avatarurl=$post[avatarpath];
		} else {

and replace that with this:

		if ($post[avatarid]!=0) {
			$avatarurl=$post[avatarpath];
			$imginfo = getimagesize('/path/to/your/images/folder/' . $avatarurl);
			if ($imginfo[0]>50) {
				$moreimgtag = 'width="50"';
			}
			if ($imginfo[1]>50) {
				$moreimgtag .= 'height="50"';
			}
		} else {
			$moreimgtag = '';

and now add $moreimgtag to your postbit_avatar template.