Firmware versions for PX-712A/SA/UF
Support for newer DVD+R media.
Support for newer DVD-R media.
Write performance on DVD+R media.
Write performance on DVD-R media.
Read support for DVD+R DL media
That is from Plextor Europe's website, so I would say that "their" firmware is correct.
Actually, the list is incorrect.
Write quality on DVD media.
Initialisation time for DVD-R media.
Read support for DVD+R DL media.
Incorrect recognition of DVD+RW media that is written by some non-Plextor recorders.
As you can see above, DVD+R9 read capabilities were added way back in 1.03.
Now, Plextor-Europe should have listed it as DVD-R DL read capable in 1.07. I could not be bothered to tell them, I will let somebody else inform them of the mistake.
The reason the PX-712 doesn't report +/- DL 9 support in *any* software is simply that it uses a non-standard flag in it's firmware. I can assure you that as of 1.07 both formats of recordable DL media is 100% readable (purely cosmetic, as arossetti mentioned), Plextor does like to do things differently/their own way, which for me is usually to my benefit