I have a PC running Win7 x64 Ultimate that I use as my HTPC and a second gaming machine for LAN gaming.
On occasion (maybe happened twice in a month) when resuming from standby I get a BSOD with Stop 04. Then I press the reset button and when it tries to boot it can't find GRLDR, so I assume it can't see the HDD properly. After turning it off and doing a cold boot it works fine.
It has 1TB Samsung HD103UJ and a 640GB WD 6400AAKS. The Samsung is the main boot drive and there's a copy of grldr on both the C: and D: partitions. There's actually a copy on the WD I: partition as well, so I guess the boot error suggests that neither drive was accessible.
Looking at the SMART info in HD Tune, it shows only a warning for both drives on (C7)Ultra DMA CRC Error Count, with data of 29 for the Samsung and 2 for the WD. These errors could have accumulated a long time ago, perhaps when I was using a different cable though and there's no way to know if any have been recent.
Device Manager shows it's using the Standard AHCI 1.0 Serial ATA Controller but I've just let it update online to the AMD SATA Controller, so maybe that will help. The board is a Gigabyte MA780G-UD3H http://www.gigabyte.com/products/product-page.aspx?pid=3004#ov with 8GB RAM and a 6850 graphics card.
Looking at the System log, the only clue before it BSOD is at 08:48 (the line before shows it resumed from sleep at 08:44):
"The driver detected a controller error on \Device\Ide\IdePort1."