[plt-scheme] scheme in captions in SLaTeX?

How does one put \scheme{} inside a \caption{} using SLaTeX?  Without
using {schemeregion}, I get:

! Argument of \@caption has an extra }.
<inserted text> 
                \par 

With {schemeregion}, I get:

! Undefined control sequence.
\frenchspacing ->\sfcode `\.\@m \sfcode `\?
                                           \@m \sfcode `\!\@m \sfcode `\:\@m...

no matter where I put the {schemeregion}.

Any ideas?

--dougo at place.org