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A lot of earlier 1213S drives had quality problems due to being calibrated with dirty laser lens'. Cleaning the lens improved the reading but not the writing as the calibration data, in the EEPROM, is wrong.
To prove this; the first thing you have to do is to crossflash the drive to 1633S firmware, probably BS0S. The second thing you have to do, is you have to dig deep in your pocket and buy some good quality media (Ricoh, Verbatim, Sony, Prodisc...). Don't burn slower than 4x and faster than 12x.
Read the Liteon forum FAQ and the Recording Hardware forum FAQ and especially learn about the tools that allow you to scan your burned discs for errors. Let us know how you get on...