From zebadee's link:
Notice：Regarding PX-760A Firmware Download-Unofficial Version 1.01
Please be noted that Firmware 1.01 has not been released by Plextor officially, and it is not recommended that you download this firmware from any other web site. The installation of this unofficial version may cause damage to the drive, for which Plextor will bear no liability.
I don't understand, it's already in Plextor.jp and Plextor.com (USA).