biblatex-biber fails: "loadable library and perl binaries are mismatched"

[bernardkelly (Bernard Kelly)]

I have a short LaTeX document that requires biber. I installed "biblatex-biber", and it seemed to go fine. But when I run

pdflatex <documentname.tex> biber <documentname>

... I get the following error:

Magic.c: loadable library and perl binaries are mismatched (got handshake key 0xc500080, needed 0xc400080)

Macports is up to date, as are all the ports. I uninstalled & reinstalled biblatex-biber, but no difference.