Sony DVD burner

I have a Sony DVD±RW DW D56A on a Dell Inspiron laptop running Win XP SP2. I burned a movie onto a DVD + R disk with no problem. Now every time I try and burn something the burner looks for a DVD-R disk. I have tried Nero, ConvertXtoDVD and Imgburn all with the same results. Ideas? Driver version is 5.1.2535.0 dated 7/1/2001