Thanks for following the tutorial and for your feedback.I have seen that happening some time ago. As far as I remember it happens when you mix up 32bits and 64bits code. In those cases you need to do some extra work to invoke the system call. I'm not sure if I took notes from those tests but I'll let you know if I found them.
I have running it with dash (my /
bin/sh is a link to
/bin/dash) and it was working fine.
To know more about how the mixing on 32bits and 64bits code works I recommend the two following brilliant articles. Specially part 2 explains how this mix is managed by Linux.
Hope this helps