From a general animation standpoint, 39 fps is overkill. Just for reference, film is done at 24 fps. Video is done at 29.97 fps. The increase in fps poses two risks. One, obviously, is file size. The second is that it's more taxing on the viewers computer. The simplest way do figure out the retiming thing would be to use a real simple animation. Just bounce a ball or cube or something and make it your goal that it hits particular spots at particular times. You can create a test project real easily and figure things out this way. It'll be easier than having to render out a poser scene so you can see if the mouth is moving right. Once you've got the simple version down to where you understand what the contols/settings do, then you test it on moving mouths. You could even use the "head" figure that comes with Poser so you don't have to render everything else. Just an idea...

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