DVD-RW disc showing zero bytes

Please Help.
I am trying to burn a movie with my Sony VAIO desktop DVD±RW drive. The DVD disc (DVD-RW) when inserted into the drive shows 0 bytes Free space and 0 bytes total space. I get an error message when I try to write to the disc. I have XP SP3. According to the microsoft web site, SP3 is supposed to fix this problem.

any pointers would be much appreciated. thanks
V

Use a REAL burning app.