Yep tired that too. The firmware is only for the Victor OEM drives. I still tried to update with that firmware anyway, but it did not recognize the drive.
For the UJDA 745 they have a section that is for SONY drives only. No such area exists for the UJDA 755 on the firmware updates.
I will keep looking, but i am beginning to think that there is not a firmware update avialable fot the UJDA 755