Loading circular package from Rprofile.site

Hi,

I installed "circular" package and I wanted to load it automatically
when R starts up, so I added the following lines in file
Rprofile.site,

.First <- function()
  library(circular)

When R starts up, it gives me the following error:
----------
Loading required package: boot
Loading required package: graphics
Loading required package: stats
Error : .onAttach failed in attachNamespace() for 'circular', details:
   call: fun(libname, pkgname)
   error: could not find function "packageDescription"
Error: package/namespace load failed for ?circular?
----------

What's surprising is that instead of loading "circular" from the
Rprofile.site, if I run R and load this package

library(circular)

it works fine and gives me the following message:
----------
Loading required package: boot
Package 'circular', 0.4-3 (2011-07-18). Type 'help(Circular)' for
summary information.
  Please report any bugs or comments to <Claudio Agostinelli> claudio at unive.it
  The package redefine how function 'var' and 'sd' works
  In particular, (try 'methods(var)' and 'methods(sd)')
  notice that 'var.default' ('sd.default')is an alias for the original
'var' ('sd') function
  and that a method for data.frame is available.


Attaching package: ?circular?

The following object(s) are masked from ?package:stats?:

     sd, var
----------

I am puzzled as to why there are different responses to the same
command? FYI, I am running R version 2.15.2 (2012-10-26) on Windows 7,
i386-w64-mingw32/i386 (32-bit)

I have other installed packages, which load up fine from the
Rprofile.site at R startup. The error seems to occur only with
"circular".

Ved