[XeTeX] Polyglossia/makecmds: Old document fails to compile

[Gareth Hughes]

Dear all,

I'm sure there's an easy answer to this, but it's always frustrating
when old documents suddenly do not compile any more. I'm writing a
fairly straightforward academic article with the first three lines


> \documentclass[headsepline]{scrartcl}
> \usepackage{fontspec, polyglossia, xcolor, soul, makeidx, hyperref}
> \usepackage[english=british]{csquotes}

When I compile the document, it stops with the message


> (/usr/local/texlive/2011/texmf-dist/tex/latex/makecmds/makecmds.sty)
> ! Undefined control sequence.
> l.402 \define at boolkey
>                      {polyglossia}[xpg@]{localmarks}[false]{%

Any thoughts on how to overcome this and get the document to compile?

Thanks,

Gareth.