Yes, the older revision BE6-2's like mine (Rev .4? not sure) had a buggy UDMA66 controller in that it was rather picky about which UDMA66 hds would work with it. I had a Maxtor 20gig UDMA/66 hd that I thought was running ok, HDTACH reported benchmarks that were consistent with UDMA66 drives, but BSOD screens would pop up now and then and only went away when I switched the drive over to the regular UDMA/33 channels and disabled the UDMA66 ports. HD performance dropped accordingly, at least benchmarkwise, though I really did not notice that much difference.