I just updated to R 2.11.1 and after installing ggplot2, I tried
library(ggplot2)
and got
Loading required package: proto
Loa
Also have had troubles, when installing ggplots2, but here is a curious solution (tested on windows):
I installed via RStudio. Both from Tools->install packages and by typing install.packages("ggplots2", dep=T)
. It didn't work because it kept not installing the dependencies.
I then installed direct by R gui install.packages("ggplots2", dep=T)
and everything went well.