DVD drive write problem

Question

Hi,
I have a Dell Inspiron 630m and the NEC ND-6650A DVD RW Dual Layer Burner disc drive has just stopped allowing me to record. I get the message that the disc is Read Only when inserted. I have tried different discs type and make fresh out of the pack all of which worked ok before this problem. Windows says that the driver is current.
Please help.
Regards
Richard