I too have had a problem which sounds similar whereby my USB device
would spin down and wait 10 or so seconds before spinning back on every
segment of a large file copy and after more research came across a
thread for bug #88746 (https://bugs.launchpad.net/ubuntu/+source/linux-
I have found that the problem seems to be with the sdhci driver.
I have posted a message at
http://ubuntuforums.org/showthread.php?t=287939page=4 under the name
skrpc detailing what I did to get a version of linux on an X56 laptop.
I had to use Debian 4 (Etch) as this was the only installation I
