I found a rendering bug in The two Inkscape Cairo versions I use (10404 and 10514) with the "Non realistic 3D shaders" filter effect.

It's linked with the first "Composite" in the tree and particularly visible when it's set on "XOR" (which is often used in thsi kind of filter).

Inkscape 0.48.1 render them correctly.

I send some examples and the filters file to test.

Thanks to take a look at.

ivan