Found my problem...
I had to change the script:
if (!function_exists('getUniqueImageURL')) {
function getUniqueImageURL($image_url){
$timestamp = time();
if(strpos($image_url, '?')){
$image_url = str_replace('?', "?$timestamp&", $image_url);
}
else{
$image_url .= "?$timestamp";
}
return $image_url;
}
}
to
function getUniqueImageURL($image_url){
$timestamp = time();
if(strpos($image_url, '?')){
$image_url = str_replace('?', "?$timestamp&", $image_url);
}
else{
$image_url .= "?$timestamp";
}
return $image_url;
}