My PC is very ancient - Intel Celeron 700MHz with MB Gigabyte GA-6VMML,
VIA VT8601 chipset, VIA Bus Master IDE controller and Microsoft IDE drivers 5.1.2600.2180. Primary master HD WD80Gb. PX712SA TLA0107 (0105 originally), SN133xxx, manufactured - September 2004. Only one strange thing happened - recently i've found that my PX712 refused to burn at 12x on Verbatim MCC 003 DVD+R 8x, although few days before I made some 12x burns (both FW1.05 & FW1.07) using same Verbatim MCC 003 DVD. Need to say, that after previous 12x burns I installed some software - Nero InCD, DVD shrink, DVD decrypter, IFO edit and Pinacle DVD studio 9. Then Pinacle was removed. Some time later, I discovered that PX712 working in PIO mode and I can't to resume DMA. So, I rolled back the system and now again UDMA2, but there is no 12x. Since after some test my best result on MCC 003 DVD+R 8x was 6x burn (PIE 11586 max 9 and PIF 737 max 3) I'm not forcing this little problem for the moment. No other issues yet, the drive is very good!
Sorry for delay with answer.