It's not possible to burn DVD RW with SONY DRU-800A

Could you help me, perhaps it's not the good way but it's not possible by an other way for me. In the past I have burn many DVD-RW, but since a few days it's not possible. I have downloaded an utility DriveCheck.exe and the new firmware KY06, and I have installed KY06,when I use DriveCheck.exe at the begining I must insert à "blank" DVD-RW after the utility don't reconnize the "media" and stop the test.
After I have executed the recommandation of "Sony Storage Technical Support" "o Change both Device 0 and Device 1 to PIO only" the result is the same. I don't known what I must do.
Have you an recommendation.
Best regards.
PDupont1
P.S.
-1)when I use an DVD-RW burn with the same DRIVE DVD RW DRU-800A with DriveCheck.exe :
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Unique Disc Identifier : [DVD-RW:MCC 01RW4X ]
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Disc & Book Type : [DVD-RW] - [DVD-RW]
Manufacturer Name : [Mitsubishi Chemical Corp.]
Manufacturer ID : [MCC 01RW4X ]
Blank Disc Capacity : [2,298,496 Sectors = 4.71 GB (4.38 GiB)]
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[ DVD Identifier V5.2.0 - http://DVD.Identifier.CDfreaks.com ]
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-2)when I try to burn a "blank" DVD-RW with the same DRIVE DVD RW DRU-800A with DriveCheck.exe :
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Unique Disc Identifier : [Not Available ] [Not Available ]
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Disc & Book Type : [DVD-RW] - [DVD-RW]
Manufacturer Name : [This Info will be Retreived from Manufacturer Database]
Manufacturer ID : [Not Available ]
Blank Disc Capacity : [Decimal Gb (1000) Followed by Binary GIB(1024)]
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[ DVD Identifier V5.2.0 - http://DVD.Identifier.CDfreaks.com ]
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