Thanks for the tip, bvh are always welcome. I'll try them as soon as I get a chance, from what you wrote, it sounds like they will need some "blanket" adjustments in the graph editor to drag the rotations or bends back to normal. If you've not used those before PhilC's tutorial here
http://www.philc.net/tutorial7.htm is a useful start, and I found some further tips on the product page for his bvh editor