panel.superpose solved

["Robert M. Key" <key@Princeton.EDU>]

Thanks to Jim Pratt for a very quick solution. The problem was with colors
in 

xyplot(c14~silicate|Latfac,data=junkdf,
        layout=c(3,1),
        panel=function(x,y,...){
                panel.superpose(x,y,groups=Zfac,subscripts=T,
                        col=superpose.symbol$col,
                        pch=superpose.symbol$pch[1:4],
                        cex=superpose.symbol$cex)
                abline(-70,-1,lwd=2)
                })

not being set correctly for Zfac in the subplots.

The solution is:

xyplot(c14~silicate|Latfac,data=junkdf,
        layout=c(3,1),
        groups=Zfac,
        panel=function(x,y,...){
                abline(-70,-1,lwd=2)
                panel.superpose(x,y,
                        col=superpose.symbol$col,
                        pch=superpose.symbol$pch[1:4],
                        cex=superpose.symbol$cex,...)
                })