The full size of the figure as given to
PostScript is the full ``figure
region'' of an S plot, including the margins, whether or not they
are used. When included in LaTeX room will be left for these margins.
If this is not wanted, a par()
command should be used in S to
reduce the margins, for example
par(mar=c(5,4,1,1)+.1)to remove (most of) the top and right-hand margins.