span parameter won't work in geom_smooth

[GuangchuangYu]

In reading the book, I found the figures in page 19 are almost identical with different span parameters (0.2 and 1 respectively).

I believe it may due to the figure size that is too small and try to enlarge it and recompile the chapter.

I got identical figures with several try (ggplot2 version = 1.0.1.9003).

 require(ggplot2)
 require(gridExtra)

grid.arrange(
    ggplot(mpg, aes(displ, hwy)) + 
      geom_point() + 
      geom_smooth(span = .2),

    ggplot(mpg, aes(displ, hwy)) + 
      geom_point() + 
      geom_smooth(span = 1),

    ncol=2)

I removed the latest version of ggplot2 (installed today, Aug. 25), and re-install it from CRAN (version = 1.0.1).

With this version, span works:

There may be something wrong in the newest version of ggplot2.