I recently purchased a spool of verbatim 8x dl-dvd's. After getting "no reference position found" with imgburn, I went and looked around for a solution. I ended up cross-flashing my HP drive to it's proper Lite-on firmware, which didn't solve the problem, but gave me more features for my drive (such as bitsetting). After finding no solution for why my drive wouldn't read media that it SHOULD be able to read, I went and purchased some 2.4x DL-DVD's, which had worked once before. Today those came and and they don't work either :/. My drive is a Lite-on LH-20A1H with the LL0D firmware.