I am dual-booting Windows 8 and Ubuntu 12.04. My partition scheme looks like this:

/dev/sda1 - Windows 8 (nfts)
/dev/sda2 - Ubuntu / (ext4)
/dev/sda3 - Ubuntu home (ext4)
/dev/sda5 - swap
/dev/sda6 - Shared data partition (exfat)

(First off, yes I do have exfat libraries installed on Ubuntu)

I created some PNG images in Windows and saved them on my shared partition. From Ubuntu, I edited the images in GIMP and saved them (replacing the ones on the shared partition).

When I boot into Windows, the files appear unchanged - exactly like they did before I edited them from Ubuntu. I even added a folder and deleted some other files, but none of these changes exist in Windows.

When I boot into Ubuntu, all of the changes are still there.

It is as if Windows is caching the old file structure...

How is this possible? Thanks in advance.

Edit -- commands output

~~ lsblk

NAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda      8:0    0 465.8G  0 disk 
+-sda1   8:1    0 165.1G  0 part 
+-sda2   8:2    0  21.3G  0 part /
+-sda3   8:3    0  98.9G  0 part /home
+-sda4   8:4    0     1K  0 part 
+-sda5   8:5    0   7.8G  0 part [SWAP]
+-sda6   8:6    0 172.7G  0 part /mnt/shared_data

~~ /etc/fstab

# <file system>                 <mount point>       <type>  <options>           <dump>  <pass>
proc                        /proc           proc    nodev,noexec,nosuid 0       0

# /dev/sda2
UUID=8f700f65-b5c7-4afc-a6fb-8f9271e0fb5e   /           ext4    errors=remount-ro   0       1

# /dev/sda3
UUID=f0d688b7-22bd-4fa7-bc1b-a594af2933fa       /home               ext4    defaults        0       2

# /dev/sda5
UUID=3bc2399b-5deb-4f04-924b-d4fc77491997   none            swap    sw          0       0

# /dev/sda6
UUID=F2DE-BC47                  /mnt/shared_data    exfat   defaults        0   3

~~ /etc/mtab

/dev/sda2 / ext4 rw,errors=remount-ro 0 0
proc /proc proc rw,noexec,nosuid,nodev 0 0
sysfs /sys sysfs rw,noexec,nosuid,nodev 0 0
none /sys/fs/fuse/connections fusectl rw 0 0
none /sys/kernel/debug debugfs rw 0 0
none /sys/kernel/security securityfs rw 0 0
udev /dev devtmpfs rw,mode=0755 0 0
devpts /dev/pts devpts rw,noexec,nosuid,gid=5,mode=0620 0 0
tmpfs /run tmpfs rw,noexec,nosuid,size=10%,mode=0755 0 0
none /run/lock tmpfs rw,noexec,nosuid,nodev,size=5242880 0 0
none /run/shm tmpfs rw,nosuid,nodev 0 0
/dev/sda3 /home ext4 rw 0 0

/dev/sda6 /mnt/shared_data fuseblk rw,nosuid,nodev,allow_other,blksize=4096 0 0

binfmt_misc /proc/sys/fs/binfmt_misc binfmt_misc rw,noexec,nosuid,nodev 0 0
gvfs-fuse-daemon /home/matt/.gvfs fuse.gvfs-fuse-daemon rw,nosuid,nodev,user=matt 0 0