Good news everybody.
I found the 1.0d firmware at this site and the link is still active. Get it while its still there man.
The 1.0d firware is going to fix all the Ritek media compatibality problem you have with the 1.0f firmware.
One downside though... you can't burn DVD+R at 4X...only at 2.4X
YOu still can burn DVD-R at 4X using the cheap Ritek media.
http://www.ebisschop.nl/dru-500a/
I previously upgrade to the 1.0f firmware and there was so much problem with it when using the Ritek media.
If you are having this problem... just de-grade to 1.0d frmware. My DRX-500UL is back to its working state now... hehehe
So do enjoy the firmware.
When you reached the website, just scroll down to the DVD-RW section. The 1.0d firmware is there.... together with a bunch of crappy 1.0f firmware.