I never thought that the actual keyboard might be reporting them the same. I can't get any info out of xev because it reports the modifier (shift) and other keys separately. But that makes me think: Couldn't Ryzom detect them separately too? X11's keycode for left arrow is 113, and for numpad4 is 83. Left shift 50, right shift 62. So (r/l)shift press + 113 press&release = shift+left and (r/l)shift press + 83 press&release = shift+numpad4.