Hmm... the media that you're trying to use, MBIPG101-W04 is a media code that was just added in US0Q (all the 812S firmwares before US0Q do not support this media code). As US0Q is the first 812S firmware to support this media code, I wonder how reliable that support is... anyway, here are a few things to try...
1/ First off, have you tried burning this disc using another app, such as DVD Decrypter or CD-DVD Speed? Have you tried erasing the disc?
2/ You might want to try using VS0G (or even CG5G), as these firmwares are about 5 months newer than US0Q, so hopefully, they might have better support for this media type.
3/ If the first two suggestions don't work, then I would suggest that you use the EEPROM Utility to make a backup of your current EEPROM (so that you can undo this if you want) and then use the "reset learnt media" function to reset the drive's learned laser calibrations. This has been known to sometimes help with burn issues that occur after upgrading from a very old firmware to a fairly new firmware.