It seems that if you put the outbound tracking on that the code on line 467-468 is not working probably and causing double quotes too early in the onclick argument.
My fix:
//if (preg_match('/onclick=[\'\"](.*?)[\'\"]/i', $matches[4]) > 0) {
//$matches[4] = preg_replace('/onclick=[\'\"](.*?)[\'\"]/i', 'onclick="' . $coolBit .' $1"', $matches[4]);
if (preg_match('/onclick="(.*?)"/i', $matches[4]) > 0) {
$matches[4] = preg_replace('/onclick="(.*?)"/i', 'onclick="' . $coolBit .' $1"', $matches[4]);
Not sure why you would allow single quotes here, couldn't find any on my own blog.