The bridge IC inside your enclosure is a JMicron JM20329.
http://sourceforge.net/p/smartmontools/mailman/message/27932627/
The OP in that thread writes …
“I have an Icybox IB-319 (IB-319StUS2-B) (EAN 4250078184485 ) - it has a JMicron JM20329 USB bridge chip in it. When connected over either USB or eSATA, running smartctl can make the bridge chip lock up.”
I don’t know whether your particular bridge is problematic, but I have personally experienced problems similar to yours when using a JMicron JM20337 and an IDE drive.
https://bigacid.wordpress.com/2008/12/08/jm20337-read-data-corruption-solution/
