USB stick unsafely unmounted cannot be written to

1. Insert the memory stick
2. Take a file big enough (mine was a 35 MB Morphix ISO), copy it to the memory stick
3. Unmount the memory stick from nautilus right click (in the folder window).
4. Wait until the notification appears saying that the user should wait.
5. Ignore this, take out the memory stick.

Do the above a number of times.

This will result in an error in the end, when you try to copy a file to the memory stick.