Like jmbach said, I'd leave the TiVo drive away from the PC for now and hook up the EURS and run wdparm -N /dev/sdc just to see what it reports. But not just yet. That BIOS setting that's disabled I'd leave disabled, but you should check and see if the current version of the BIOS on that board is the latest for that board. I googlestumbled across some GB HPA talk that said some boards had BIOS'es that had the disable option (mine don't, they're older), but there's a bug in the BIOS that prevents disabling from actually disabling. Although if it weren't disabled I would have expected it to have HPA'ed the SSD Anyway, check your BIOS version, check GB's website to see if there's a newer version, and google the board number and BIOS number to see if anybody mentions anything about the HPA problem. You'll probably have to try several different combinations of the various pertinent search terms.