Attaching External Images to Invoice Templates

Attaching External Images to Invoice Templates

I have built a template that uses external images (stored on http servers) to display really good looking invoices. In the browser the images show up fine in the template. (<img src="http://xxxxx.com/images/invoice.jpg">) but when it prints to PDF, the only image that shows is the LOGO image that was set in the settings.

Is there a way to get your PDF builder for ZOHO INVOICE (AND ZOHO CRM) to include external images in the Invoice?