First, please know that I've already checked out the other threads on the subject and none of the solutions have worked in my case.
Having said that, I recently upgraded the memory and replaced the mobo in my HTPC. Below is my current setup:
Gigabyte MA790X-DS4 mobo
AMD Athlon 64 X2 4200+ processor
4 GB DDR2-800 RAM
Maxtor DiamondMax Plus 8 40GB IDE HDD
Maxtor 6V300F0 300GB SATA HDD
Western Digital WD10EACS 1TB SATA HDD
Running under Vista Home Premium (upgrade from XP Pro)
Before performing any upgrades the entire system was running just fine (albeit a bit on the slow side with only 1GB mem). After replacing the motherboard I found that the BIOS couldn't find the 300GB Maxtor SATA drive. The WD one works just fine. If I shut down, unplug the SATA cable, plug it back in, and reboot everything works great... until I reboot again.
I've tried updating the BIOS, using different SATA cables, different power cables, different SATA ports, re-installing Windows using a SATA/RAID driver disk, and uninstalling the SATA/IDE controllers in Windows (allowing Windows to re-install them automatically). About the only thing I haven't tried is voodoo, though if anyone thinks that'll work I'm certainly open to giving it a shot. It's also worth noting that SATA is enabled in the BIOS, but the autodetect feature won't find the disk either.
I'm about at my wit's end here. Any help would be greatly appreciated!!