Odd. I have burned RITEK-S04-66 with my Pioneer DVR-115D and no issue except that the quality was a bit low. I also have the SATA version of your writer so I'll try to burn a disc with it also. Your Pioneer should also work well with Verbatim 8x rated DL discs, if you can't find the ones mmalves suggested. Get the Verbatims labeled 'Made in Singapore'.