The most common reason is that we simply have not received your final shipping address and a picture for the DVD cover. Our system automatically sends out an email asking for your current shipping address and a picture. We will not send out your DVD without receiving confirmation that your shipping information is current.
The other reason is that the final video was not approved through the Approval page. Check your Project Status to make sure your approval has gone through.
If all the above is correct, feel free to contact us to find out the status of your DVD.