I am relatively new to DVDfab, however, I was able to copy DVD to DVD using the free trial version for 20 to 30 DVDs without a problem. Now, over the past few days, every time i put in a blank DVD +R, DVDfab is telling me that it is single layer media and I need to insert double layer media. Why would this happen all of a sudden? They are the same exact blank DVDs I had been using previously without a problem?