" I've got a dualbootsystem... and the Serial ATA controller, with it's SATA-HD attached to features my second OS... so disabling it from the bios isn't an option I've got."
You only have to disable hde during the install so that the SuSE installer cannot find it when it scans all of the available hardware. You can enable hde again after the install is over. If you cannot disable hde in the BIOS then you could unplug the SATA disk until the install is over.
Be prepared. Create a LifeBoat CD.