2 suspects are the VIA IDE drivers (I hear there's a recent upgrade) and the Promise controller. Nothing wrong with the Promise itself, but if you feel like experimenting you can try running Mtkwinflash after disabling it. Of course by that time you're faster just flashing in DOS with Mtkflash
BTW, do you have good experience using the official Liteon Windows flasher on this configuration?
Oddly enough, the official Lite On firmware is no problem. It's worked everytime.
I was thinking it would be a problem with the Promise ATA66 controller too (BusMastering causing a problem?). But it's too much work to start pulling the card & removing VIA drivers.
MTK Flash (DOS) worked. I flashed it back before the post. All is well again.
As I said, the program shows great promise, just not with my system.