For a new PX-850A rebadge of the LiteOn IHA322, here is what
I find with what appears to be the peaceful co-existence of the
following three familiar items on WinXP Pro SP3:
 Newer PlexUtilities_1.17 -
Useful for obtaining the unit firmware and the PlexUtilities
updates that Plextor has yet to provide on their web-pages.
The only way to set drive spin-down and standby settings
(if you don't reboot, at which point your settings get wiped).
The only so far found way to do "BLER" (C1/C2 and PIE/PIF)
with this drive. Thanks, Plextor ...
 PlexTools LE_3.13 -
Able to display the most basic optical drive information, set drive maximum read speed, L-R Audio Channel slider levels, toggle
Auto Insert Notification, Buffer Underrun Proof, and DMA.
Can do Disc Info and appears to have all other "Disc Functions".
Appears to perform CD Read Test, Read Transfer Rate test,
and Write Transfer Rate Test. C1/C2, FE/TE, and Beta/Jitter are
all disabled and non-functional.
For DVD, the situation is the same. PI/Po, FE/TE, Beta/Jitter, and TA
are all disabled and non-functional.
 Nero CD-DVD Speed_4.7716 -
Benchmark, Disc Info and Scan Disk work, but the desired Disc Quality
tests are disabled and non-functional. Further, Bitsetting in the Extra
menu is also disabled and non-functional.
As for bitsetting, PlexUtilities does not support it, Nero (6.615a)
does not see the drive in order to make it a settable option, and
even the LiteOn utility for Bitsetting on the iHA322 won't play ball
(the custom Plextor firmware is declared incompatible). Sigh ...
In Fairness: maybe a newer version of Nero might "see" this
drive for bit-setting (or the bundled Roxio Creator CE_10 might
do this). I'm a Nero kind of Guy, and I don't particularly have to buy
the latest version (that would cost the same $50 that the dang drive
has). Bitsetting (thankfully) is less essential for players these days.
I have not tried the rather crude-looking LiteOn diagnostic utilities
for the iHA322 - I suspect they won't play ball with the Plextorian
If Plextor chooses to render this drive unusable by any other -
they really ought to (without prejudice to Kprobe) provide
support software that would (at least) equal the comprehensive
functionality of the (free) PlexTools LE_3.13. At least, they might
address the bugs that they (or someone) has left to date in the
Conclusion: It appears to be worthwhile to kluge the PlexTools
(2.35 in my case) in along with the PlexUtilities (1.17), but it appears
that the user is stuck with the modified Kprobe Disc Quality functions.
Note: Any suggestions from folks messin' with this Plex-On 850A
who have found or might suggest other options to try with this
drive are welcome ... ! I sure would like to find some options to use
for Disc Quality scans.