Pioneer released a new firmware for the Pioneer 107d, DVR-A07XLA & XLB. It's version 1.18.
DVD-R Writability Improvement
+R Writability Improvement
DVD-RAM Playability Improvement
CD Playability Improvement
+R DL DoubleLayer Playback Implemented (NOT Record) http://www.pioneeraus.com.au/computer/firmware.html
I tested the new fw with DL media burned with and with out bitsetting to DVD-ROM and it works fine, this is good news as DL is becoming more common now.
To bad it cant write DL, I guess you cant have everything.