How do I get these animated obstacles to work right with fluid physics and prevent freak outs like this? I recently tried to bake a fluid physics simulation with a mixing vat style setup. I did some basic parenting and keyframes to animate the stirrer, but the fluid immediately freaked out completely (or as immediately as it could have been, considering it baked for 3 days).

https://www.youtube.com/watch?v=5Mli_sOjYDc

What settings do I need to change to keep this from happening? I've heard about something called exporting an animated mesh, but I can't seem to find anything on the internet about it.
Select your obstacle object, go to physics in the properties pane, under fluid obstacle settings there's a checkbox called Export Animated Mesh. Use it :-)