How Do I Stop the DVD Drive from Disappearing When Burning with Encore CS6

Having Edited a Movie in Premier Pro CS6 and using Encore CS6 to burn the DVD.

During the burning process the DVD Drive Disappears and i cannot complete the project.

The Only Way I Can Retrieve the Drive Is to Reboot.

After the reboot the drive will be there however I May or May Not Have Success in burning the DVD using Encore

i have used the DVD drive for many other operations without having a problem

e.g. loading programs, reading information, copying discs, listening to music etc.