This will upgrade the firmware of a Sony DW-U10A DVD Burner to DW-500A 1.0g. Then you can get the most current update for the 500A from the Sony site. At thew time of posting this, the most current update is 2.0h.
This HAS been tested by me and it worked on a WinXP Pro machine. I hope it helps you too. I found it originally on a dutch site.