Sony VAIO does not recognize blank DVDs or CD-RW blank disks

Hi.
I have a Sony VAIO desktop with Pioneer DVD-RW DVR-106D drive with 5.1.2535.0 driver.
I can play DVDs and CDs and write to regular blank CDs, but cannot get it to recognize either blank DVDs or blank CD-RW disks.
Note that my other Sony VAIO laptop has same problem.
They are both running WinXP.
Thx for any help.
Bob