[R-sig-Geo] SP 1.0-12 install error

[Alex Mandel]

I was getting an error today installing/upgrading sp.

Error in setClass("CRS", slots = c(projargs = "character"), prototype =
list(projargs = character(1)),  :
  unused argument(s) (slots = c(projargs = "character"))
Error : unable to load R code in package ‘sp’
ERROR: lazy loading failed for package ‘sp’

I tried uninstalling/reinstalling, using a different mirror, doing it
system-wide vs just for my user etc... Then I noticed that 1.0-12 was
released only a few days ago, so I downloaded the archived version of
1.0-11 and the install works.
http://cran.r-project.org/src/contrib/Archive/sp/

R is 2.15.3 on Ubuntu 12.04

Is there a bug in the package or does the new sp require R>3?

Thanks,
Alex