Vista is very unforgiving. I forgot to make a destination folder before running a RoboCopy script to back up my portal hard drive.
The trick to fixing this can be found (with much searching on Google) at http://support.microsoft.com/kb/326549.
In short, run this in a command window (be sure to open the command window as Administrator)
attrib -h -r -s drive:\<path>\<foldername>
Example:
attrib -h -r -s c:\test