[eluser]OverZealous[/eluser] @bojack
The query is correct, at least as far as having the joined columns.
Have you tried running that query manually on the server? Is it returning the correct results?
Try calling get_raw instead of get, and looking at the CodeIgniter query result directly, to make sure that the results are correct there.
Assuming the queries are returning the exact same results, try using include_related without instantiating, and see if that works. If that works, then most likely something is happening on the server that is causing $posts->_instantiations to be unset or set to NULL.