OK - BIOS is now successfully flashed with a BIOS which specifically - so MSI says - was to upgrade the SATA firmware. But it aint done me no good. SATA drives are still not recognized by the BIOS or - obviously, PCLOS. And this was with a new install from the latest ISO of Gnome. So now, thank you guys for your help and advice, but I really have no more time to spend on this. Some you win, some you lose. This mobo will, henceforth, carry only IDE drives.