Try the nhexl-mode below on a buffer.
You should see that the first line of the buffer is displayed
differently from the rest (the first line is displayed the way I'd want
it).  On the subsequent lines, the `face' properties as well as the
`display' properties on the before-strings seem to be ignored (or
something like that).

This minor mode seems to hit several other bugs, but let's start
with this one since I haven't found easily reproducible test cases for
the other ones yet.


        Stefan