If you're referring to my statement about the flashing process becoming unstable, it was taken from the AOpen web site FAQ's. Here's the quote in it's entirety:
<TABLE cellSpacing=4 cellPadding=4 width="80%" align=center border=0><TBODY><TR><TD align=left>Can I flash (upgrade) the firmware in DMA/UDMA mode? </TD></TR><TR><TD align=left>It's not recommended to do so. In DMA/UDMA mode flashing process may become unstable and damage the flash ROM.
To flash the firmware, please follow steps listed below: Assuming that the CD-RW drive is connected to Secondary Slave on the IDE channel of AOpen AK73 Pro motherboard:
1. Disable UDMA support or set the device to PIO mode in motherboard's BIOS:
Go through BIOS Setup -> Integrated Peripherals -> IDE Secondary Slave UDMA -> Disabled.
2. Boot into OS to disable UDMA:
I. For Windows 98/ME, go through My Computer -> Properties -> Device Manager -> CD-ROM -> AOpen CRW-1232 Pro -> Properties -> Settings -> Uncheck the DMA box
II. For Windows 2000, go through Control Panel -> System Properties -> Hardware -> IDE ATA/ATAPI Controllers -> IDE Secondary Channel -> Advanced Settings -> Transfer Mode -> PIO Only
3. Restart system, in OS run RFLASH.EXE to upgrade firmware.
4. Restart system, restore previous UDMA settings.
Since I've had both failures and sucesses in flashing in UDMA, I'm starting to think it depends on the particular drive. Are you saying that the Pioneer cannot be flashed in PIO mode?