Those bone 'riods seem to be causing problems...

They do, in large numbers. IIRC, they have the largest textures, and each bone 'roid has a unique texture, so even on the 256MiB cards, it fills up all the texture memory, if there's a lot of them. But there's only a few scattered around Setalli Shinas L-12, I wouldn't have expected them to hurt your framerate that much...

[edit]
Just checked it out, there are more of the bone 'roids than I thought in L-12. I was getting around 30fps, which is OK, but lower than I'd thought I would get. Try turning your Distance Level of Detail down to 5~7, on the Options->Graphics screen. The 30fps was when I had Distance LOD maxed out at 20, dropping to 7 gave me around 75fps, and 5 put me at 100fps.
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[edit 2]
Nevermind, looks like you already tried lowering the Distance LOD... which puts me at a loss again.
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[edit Screenies]
Other than Distance Level of Detail, all of these screenies are with everything maxed out.

Distance Level of Detail = 5
http://mandalor.homelinux.net/vendetta/screenshots/fullscreen/Setalli-L-12-DLOD-5.jpg

Distance Level of Detail = 7
http://mandalor.homelinux.net/vendetta/screenshots/fullscreen/Setalli-L-12-DLOD-7.jpg

Distance Level of Detail = 20
http://mandalor.homelinux.net/vendetta/screenshots/fullscreen/Setalli-L-12-DLOD-20.jpg

Closer to your worst trouble spot
Distance Level of Detail = 20
http://mandalor.homelinux.net/vendetta/screenshots/fullscreen/Setalli-L-12-DLOD-20-2.jpg
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