I'm getting this error when I manually run; 'php runJobs.php' on my site

PHP Fatal error: Call to a member function insertBefore() on a non-object in /var/www/extensions/ImageMap/ImageMap_body.php on line 274

I have run a quick web search for this error but turned up nada. Just wondering if anyone could shed a bit of wisdom on this. I've upgraded Extension:ImageMap to the current stable with no different effects. I also took a look at the offending line, but I'm no php guru. Any tips appreciated. john