Just for the records, i got an Acard 6280M now, and it works perfectly inside my oldworld Macs (7600, 8500, 9600). Both, big IDE-harddisc and DVD-RAM burner work perfectly inside this PCI 2.0 slots.
My Macsense SUA-100E SATA (Projovian), doesn´t work inside my pre-G3 (PCI 2.0). But It works...