Weirdness re: inclusion of figures

[Paul Magwene <pmmagic@gmail.com>]

Hi All,

I'm trying to get up to speed with org-mode and babel for doing
reproducible computational research.  I'm just starting to play around
with simple examples, and I'm baffled by the following.

This first example, when exported to HTML or LaTeX produces the
expected result -- a simply code block with one embedded figure.

# Example 1.

This is my R example:

#+begin_src R :file z.png :results output graphics
plot(matrix(rnorm(100), ncol=2), type="l")
#+end_src

Some intervening text...

#+results:
[[file:z.png]]


However, this almost identical example, minus the intervening text
between the code and the results, doesn't include the figure:

# Example 2

This is my R example:

#+begin_src R :file z.png :results output graphics
plot(matrix(rnorm(100), ncol=2), type="l")
#+end_src

#+results:
[[file:z.png]]


What gives here? Do I always need to have intervening text between the
source code and results in order to get a figure in the exported
document?

Thanks,
Paul