The end

(hopefully) of my Motherboard catastrophy series.

Thanks to the accompanying link, I tried the acpi=off kernel parameter while having the SATA drive connected to the ICH8 with already installed Vista. Now the drive is successfully detected and this error, that I had previously is gone:

ata3.00: qc timeout (cmd exec 0xec)
ata3.00: failed to IDENTIFY (I/O Error, err_mask=0x4)

Though I do not understand what the link between ACPI und the SATA (driver?) is..