Sony CDU926S errors

[stel]

I have a Sony CDU926S CD-R writer SCSI drive. Recently I have been getting error messages and it destroys new blank CD-R's I am trying to write to. The error messages I get are as follows: -

T0100: I/O error (03/CA/00) - Disc error - power calibration area error
T7728: TrackWriter warning - Operation continues
D0100: I/O error (03/02/00) - CD recorder error - cannot seek to the requested location

Nothing has changed on my PC. I have removed the drive and SCSI card and re-installed them to ensure that there are no loose connections, as suggested in the help files on the software I use to create the CD. I have also tried to use different recording media, with varying speeds, but ensuring that I maintain 1 or 2 time write as is the specification of the CD-R writer. Could anyone please assist in trying to identify where the problems is and how to rectify it?
Thanks