You should never try and edit video off a USB drive. The data rates are to great a speed hog for the speed of USB. You probably did ok until the drives got a little more filled up.
Tell I.T. (THIS IS WHAT I NEED) and hand them back the USB raid box. Or keep it for back ups.
Export from APP – Select the mpeg DVD preset.
Dial in your data rate for max quality to space ratio.
Send to queue to render out using AME.
Take those finished files over to the computer you want to burn them to disc with.