Toshiba HD DVD Drive wont burn CDs

[sinister_monk]

Until recently everything worked fine, but a couple of days ago my Toshiba DVDw/HD TS-L802a ATA drive stopped writing to CD, this is using any application (such as NERO, image burn, windows media player, or explorer etc).
It will read CDs fine and operate correctly with DVDs.

I have done a little searching around the net and found the following to have no effect

I've updated the firmware to the latest version.
reinstalling CD applications
I''ve deleted the upper and lower filters in the registry
system restore to earlier point

I am now at a loss, so I hope you guys can help, please?

TIA

[sinister_monk]

Well I borrowed an external drive tonight and determined the problem is not a hardware one as it displays exactly the same symptoms as my drive.
Anyone any ideas, please?