Turns out it was my fault after all, I forgot about the NX bit! I was
allocating memory for the callback trampolines with lua_newuserdata,
which uses malloc, which allocates on a page without execute
permission... I took a trampoline allocator from Python ctypes that
uses mmap behind the scenes and now it works.
I uploaded a new rockspec and updated http://alien.luaforge.net. The
version got bumped to 0.3.2. Sorry for the noise. :-) I forgot I had
ssh access to a x64 machine, or would have tested on it too.
