that is true there are no drivers for optical drives and arent needed either, windows have its own generic drivers which works great,my bad i just assumed that drive on the screenshot is the only dvd burner you have not many ppl have more then one anyway i just checked that drives firmware aswell and it does support that mediacode at 6/8 speeds but that still doesnt mean the media aint at fault
have you burned at 8x?
do you have the latest firmware KS03? (dru-800a is a liteon 1693s oem and the 1693s firmware is 1 week newer then sony's)
you might wanna get taiyo yuden media from www.rima.com