I believe that the process I'm using is correct, because when I add the sample file "opendocument-writer.odt" to my site in the same way, both the html and PDF are generated correctly.
So, there must be some problematic difference between my .odt file and this .odt file. Perhaps the version of OO that was used to create it differs...or...maybe my file contains some problematic elements? Any ideas? The file appears relatively simple, with no hyperlinks or images.