SATA drive disappears every hour, back on hard reboot

I consistently lose one of my two SATA drives (one SSD, one HD) after (almost?) exactly one hour. Doesn't matter if the computer is at idle or the disk is being written to frequently. The machine is dual boot and the behavior is the same in Windows 7 and Ubuntu 10. Seems to be whichever port is closest to the top of the machine. The drive will disappear and will not remount until I do a hard (power cycling) reboot. Both drives appear to be fine.

I don't see anything in the BIOS that would do this, but 15 times in a row at between 58 and 62 minutes (maybe exactly 60) is some setting somewhere, isn't it? It's an ASUS mobo, AMI BIOS, Marvell controller for the 6GB port, but the phenomenon also happens when both drives are plugged into 3GB/s ports.

This is a known issue with older firmwares of Crucial m4 SSDs after a few months of use:

Correct a condition where an incorrect response to a SMART counter will cause the m4 drive to become unresponsive after 5184 hours of Power-on time. The drive will recover after a power cycle, however, this failure will repeat once per hour after reaching this point. The condition will allow the end user to successfully update firmware, and poses no risk to user or system data stored on the drive.

Source. You need to get at least firmware 0309 from here.

Check your advanced power settings in Windows. (I assume you're using Windows?)

Then again, are you using any special drivers that might be causing this? (Did you "install" any drive management stuff like products from Ontrack, maybe?)

Also assuming this isn't in the BIOS (which is my first guess), I would be looking long and hard at those things too. Hope it helps.