Regular permissions dialog for items on vfat disabled

For some reason, all objects on my two vfat partitions (mounted using the following fstab lines) have their regular Access Permissions comboboxes disabled. Only the advanced permissions are available. Why is this and what can I do to re-enable the regular permissions? /dev/sda1 /win/c vfat user,uid=samjnaa,gid=users,umask=033 0 0 /dev/sda5 /win/d vfat user,uid=samjnaa,gid=users,umask=033 0 0 P.S: I want to enable rwx permissions by default for all items on my vfat partitions for my user. The above settings do not seem to be able to do it. Please advise on what to do. Thank you, Shriramana Sharma.