New to ShipRush - label printing problems

I am new to ShipRush just this week. I have a FedEx account set up which is working/Printing just fine to my Zebra 500 label printer. However, the Discount Postage does not print correctly. I can get a test label to print without any problems. When I actually enter a shipment and hit print postage, at first it would not print anything at all. After restarting my computer, it will now print the label, but it has "test label" printed across the front of the label, so I can't use it. I am also unable to Void the label.

My first impression is that this would be very helpful software if I could get it to work properly.