Windows Vista - eSATA drive issues

Short version: They worked yesterday, not today.

I have a 2.0TB Western Digital 3.5 drive running through a Thermaltake
BlacX Duet, AND a Western Digital 1.0TB external hard drive.

Both are connected through eSATA ports and cables.
Both have functioned relatively flawlessly for the greater portion of at
least two months, if not longer.

Now, through restarts and puttering the 1TB drive will periodically work
as if nothing ever happened, but the 2TB in the Duet won't at all.

Neither appears in device manager, even after refreshing it or having it
search for new devices.

Power cycling the computer fails to fix this.
Power cycling the HDs fails as well.
Disconnect/reconnect fails.
Swapping ports fails.
Changing the BIOS settings from IDE to AHCI mode (and vise versa)
fails.
Updating my previous version of the Jmicron PCIE-to-SATAII/IDE RAID
Controller from v1.06.75 to v1.17.55, from the downloads at jmicron.com
fails.

The devices do not show up in the device manager, nor in the BIOS, nor
in the boot splash screen nor during the Jmicron screen which usually
lists finding both, during startup.

I'm running Vista 32 bit with all current updates.
No significant updates occurred between functioning and malfunctioning
moments.

I have not tried testing the harddrives themselves to see if they have
failed, as the likelihood of simultaneous failure of both eSATA drives
is statistically rediculous, and noting that the mybook drive
periodically and unpredictably does work, lends credence that the dock
would work too.

But beyond that, I'm starting to hit a wall in terms of troubleshooting.
Any suggestions will be taken seriously.

Please help. :-)

--
TurboNitroMonke