It appears that your web host is blocking your ability to load files from URLs using readfile. If you visit your siggy.php directly, such as
this you will get the error messages that show why it doesn't work.
The easiest fix would be to have your host set allow_url_fopen to ON in the PHP configuration. If that is not possible, you can do an update to fix the issue.
In siggy.php some modification is necessary.
Find:
PHP Code:
header ($contentType);
$status = readfile($image);
Before Add:
PHP Code:
$image = str_replace("http://upgradecruise.com/", "", $image);
If that works as I think it will it will load the files from the local filesystem rather than trying to load from a URL, which is disabled on your server. :)
If you wish to donate my email is rusnakweb@gmail.com and you can donate through PayPal's send money feature. :)