massive USB 3 problems

[jerryvienna]

Hi,
I am running Win 7 64 bit prof. fresh installed with all drivers from lenovo as of today.

However I have massive problems with an externa USB 3 Harddisk.
I loose connection to it. When just opening computer browser I see the disk but after some minutes it say "You must format your drive,..." if I cancel and press refresh the disk is there again.
Sometimes I can browse files, and even copy a small amount of files to the disk. After some 100MB the disk is "gone" and copying stops with an error. Sometimes retry works and it continues.

The drive works perfektly on other USB3 capable computers - so I guess it ist the W520 USB.

Any Ideas how to trace this down or even fix?

Thanks!

Jerry