how to reproduce:
1. mkdir /tmp/dir
2. touch /tmp/dir/a
3. dosbox /tmp/dir
4. touch /tmp/dir/b
5. "dir" in dosbox: will see "a" but not "b"
6. all the dos applications inside dosbox will not see the file "b", too
7. dosbox will see "b" only after it is re-started
This means that when I add some file using the host OS while Dosbox is running, I have to restart Dosbox
(and also restart the application inside, which is important) in order for Dosbox to see
the file :( Seems like a bug to me, because this behavior is not expected.