[Xy-pic] \xybox's in \align

[Scott Morrison]

For some reason,

\begin{equation}
\xybox{(0,-4.)*\xybox{(1.5,8);(1.5,0) **\crv{(2.5,2.4)&(0.5,5.6)},
}}
\end{equation}

works fine, producing a squiggly line, but

\begin{align}
\xybox{(0,-4.)*\xybox{(1.5,8);(1.5,0) **\crv{(2.5,2.4)&(0.5,5.6)},
}}
\end{align}

fails, generating the error

! Argument of \next@ has an extra }.
<inserted text>
                 \par
l.537 \end{align}

Does anyone know why? What's going on here?

(the xypic code is a little strange because I'm using Mathematica to 
automatically generate xypic code, using lots of nested xyboxes)

Thanks, Scott Morrison