I seem to be running into empty messages fairly often lately (maybe just bad luck to be running into them).

If you need examples, try this Google query:

http://www.google.com/search?num=20&hl=en&client=opera&rls=en&hs=pbr&q=%... [1]

If will also report many normal messages that simply contain the words "empty message" in the body, but if use your browser search function to find the exact text "[Empty message]" on each page of results, you should find many messages that are really empty, starting with the second result page.