Has anyone else had an issue with this MB and large file copies to an external HD?

I have a WD 1TB external drive and try to copy my backup files to the external drive say 165GB at one time.

If I copy the 2 files separately, it will be ok, but when I try to copy at the same time, it will either bluescreen or hang at a random point during the copy.

I noticed that Win7 sometimes has trouble shutting down with the external drive. When using the computer during the day, it will sometimes forget that the external HD is connected and not show in "my computer".

I never had this issue with the Rampage II board.