unbranded SiI0680A-based card, all drives are spinning fine, and arrays are primary & secondary masters for array 0, primary and secondary slaves for array 1
& system simply wouldn't boot from ANYTHING with the card plugged in, regardless of droves plugged in - e.g. wouldn't boot from CD, plugged into the regular southbridge IDE controller, nor from floppy, with the card plugged in - meaning i couldn't try & re-flash it.
ended up tossing the thing in the sink. will hit maplin for a replacement later