Ubuntu – Nautilus uses different permissions for mounted drives

I've written two bash scripts to give read-only or read/write access to my NTFS partition:

read-only access:

sudo umount /media/Data_Drive/  
sudo mount -t ntfs-3g -o ro,user,auto,nls=utf8,umask=0000,uid=1000 /dev/sda2 /media/Data_Drive

read/write access:

sudo umount /media/Data_Drive/  
sudo mount -t ntfs-3g -o rw,user,auto,nls=utf8,umask=0000,uid=1000 /dev/sda2 /media/Data_Drive

It works perfectly if I only use terminal to work with the files. It also works with Nautilus in read-only mode but not in the read/write mode. In fact, Nautilus gives me an error when I try to copy a file to Data_Drive saying "The destination is read-only".

More funny, when I look at the permissions (by right-clicking on Data_Drive and then properties->permissions) I have all the required permissions to write a file in Data_Drive!

I am so confused why Nautilus behaves strangely. I appreciate if anybody could solve the mystery!