Problem with UJ-841S DVD drive

I have a 6 months old Toshiba A100 with UJ-841S DVD drive which was working until recently.We are running Windows XP service service pack 2. Now when I go to my computor the drive is not recognised. Going to properties with a blank DVD in it shows Used space 0 Bytes, Free space 0 Bytes. If we put the same blank DVD in another computor it shows Free space 4.38GB. My drive will play a previously recordered DVD Movie or read a data CD. When we click on the drive in my computor with a blank disc we get “D:\is not accessible” “incorrect function”. With a previously recorded CD or DVD from this or another computor the disc will open or play okay.
Any help would be appreciated.
I have posted this earlier in another area.
Thanks Geoff