I've had the same problem with this drive twice and now my third one is about to go , The last time I spoke to Sony DVD Link Customer care line the call handler told me that this was a known problem and a fix was in the pipeline , but when I tried to question him further he changed the subject.
I'm in the process of getting a refund and switching to the Pioner 106 as this is the preferred drive for burning -r discs.
The Solution that sony seems to be happy with is that you deal with a company called avery berkel (if your in the uk dont know about other countrys) their more than helpful but it takes at least two months to get your new drive even though I pestered them daily so cant imagine the timescale if you didn't annoy them .
As for the Â£15 I've paid in postage for the two times all sony say is read your guarantee we dont pay postage especially if we just deny there is a known problem with this drive .
But look on the bright side I'll get refunded Â£260 and the pioneer drive is available for Â£130 .
I'm not knocking the drive though because when it does work ok the backup copies are superb and very few coasters are made.
But when it doesn't work its so bloddy frustrating .
Cheers for the ramble