[SoloX]

If you have RSS posts going to a forum like I do, you will have to do this:
in includes/cron/rssposter.php find

PHP Code:

$threadactiontime = (($feed['threadactiondelay'] > 0) ? (TIMENOW + $feed['threadactiondelay']  * 3600) : 0); 


right under it, put

PHP Code:

$pat = '/\[IMG\](.*?)\[\/IMG\]/i';
preg_match($pat,$pagetext,$matches);
$thumburl = escape_string($matches[1]);
$itemdata->set('thumbnailurl', $thumburl);