OK thanks for checking.

In case anyone one else runs into it I have:
Java= jre-7u17-windows-x64
Win= Windows 7 (64-bit) Professional SP1

I was experimenting and came across this by accident:

With this:
v3.5, Win 7 64-bit OS

Do this:
Select Rename & drag in some files to the left pane
Double left-click one of the files (in the left pane)

And this happens:
Application hangs and need task manager to exit.