Fedora 16 changed the default starting user numbering.
F15 and earlier started them at 500, F16 changed and now they start at 1000
you need to change the user/group numbering on the files to the new numbering in F16..
chown -R --from=500:500 1000:1000 /media/directory/*
(/media/directory/* is the mountpoint for your drive change it to what it's named on your system)