I tried to upload a test photo (58k) and post it using the file manager, but although it seemed to upload, I couldn't get it to appear in my post, and it doesn't seem to be saved if I come back to try it again.

The only thing under "Post Options" is:

HTML is disabled.
UBBCode is enabled.

Should there be another option, or am I just not authorized yet?

Always remember that you are absolutely unique, just like everybody else. -Margaret Mead