I've had this Link Removed copying files between 3 network devices - from a linux box to a vista box, via windows 7. (e.g. win7 is man in the middle as both vista, linux are faceless devices).
I've spent the whole day trying out different combinations of a set of test files trying to pin down...
connectivity issues
data transfer
error messages
file copy
file sharing
gigabit network
homegroup
linux connectivity
network configuration
network issues
network performance
networking
printer connectivity
remote differential compression
simultaneousfilecopies
troubleshooting
uac settings
windows 7
windows vista
windows xp