eSATA only errors and failures

Windows Vista has failed on many tries to copy a 160 gb folder about 30k items via any method (copy-paste, drag, right click, syncToy). It starts the process OK and then slowly grinds to a halt, apparently (no activity, lots of free resources). When I try to abort the failed operation, that cancel process fails also, and the only way to end it is by shutting the external drive down. The source is a external eSATA Samsung HD204UI; the destination is an internal OS SAMSUNG HD103SJ. They both have over 300gb free. Windows has exhibited strange behavior often in the course of these attempts, like repeatedly ignoring the copy attempt altogether. I didn't have this problem up until a week ago, but the drives and eSATA setup is new. Previously I could routinely copy large directories. Reboots help not.

I'm experiencing momentary system freezes every minute or so apparently related to the following event shown in the win event viewer:

The driver for device \Device\Scsi\JRAID1 detected a port timeout due to prolonged inactivity. All associated busses were reset in an effort to clear the condition.

Above re-occurs once per minute after boot, only when eSATA is hooked up. After failed copy, if drive is turned off and back on, errors do not occur in absence of copy operation (or other?).

Research elsewhere on that error leads to focus on two issues, for which there is a lot of discussion: the JRAID controller and the Samsung drives.

Recommended solutions:

1. disable the JMicron RAID controller (JMB36X; driver 1.17.43.5). (Doing this makes my eSATA drives disappear. I don't use a RAID setup but want to be able to hot swap eSATA drives. Doing the copy with the same drive set up as USB works fine, if relatively slowly.)

2. apply a Samsung firmware patch to allow SeaTools and sysmontools to be used.

I updated the jmicron controller driver to no avail (now 1.17.63). Though large copy operations appear to have fail and the stalls and errors return, if the drive is powered down and back up, it can be seen that the copy was actually successful and the errors have stopped.