[web2py] streamer vs stream_file_or_304_or_206

[Charles Law]

I've noticed that when I stream() files using the streamer I get
content type warnings in chrome:
  Resource interpreted as Document but transferred with MIME type
image/png.
But the static directory, which uses stream_file_or_304_or_206() does
not have this issue.

Should the streamer be returning HTTP status codes?  Should I be doing
this?  Could this be why chrome has an issue?  My controller code
currently looks like this:
  return response.stream(open(path,'rb'),chunk_size=64*1024)

Thanks,
Charles