[R] library() and install.packages() no longer working ("Access is denied" error)

[Jonathan Greenberg]

In the last week, SOMETHING on my system must have changed because
when trying to library() or install.packages() on R 3.0.1 x64 on a
Windows 2008 R2 server:

> library("raster")
Error in normalizePath(path.expand(path), winslash, mustWork) :
  path[1]="D:/Users/[UID]/Documents/R/win-library/3.0": Access is denied

> install.packages("raster")
Installing package into ‘D:/Users/[UID]/Documents/R/win-library/3.0’
(as ‘lib’ is unspecified)
trying URL 'http://ftp.osuosl.org/pub/cran/bin/windows/contrib/3.0/raster_2.1-49.zip'
Content type 'application/zip' length 2363295 bytes (2.3 Mb)
opened URL
downloaded 2.3 Mb

Error in normalizePath(path.expand(path), winslash, mustWork) :
  path[1]="D:\Users\[UID]\Documents\R\win-library\3.0": Access is denied
In addition: Warning message:
In normalizePath(path.expand(path), winslash, mustWork) :
  path[1]="D:/Users/[UID]/Documents/R/win-library/3.0": Access is denied

The permissions on that directory APPEAR to be correct (I can add
files/folders, rename them, delete them), but alas R continues to give
me these errors.  Both the users and the sysadmin claim nothing was
changed, but clearly something did.

As a heads up, I did try removing PATHTO/win-library/3.0, and re-ran
the install.packages("raster"), at which point R asked me "Would you
like to use a personal directory instead?".  I clicked yes.  It then
asks me "Would you like to create a personal library
'D:/Users/[UID]/Documents/R/win-library/3.0' to install packages into?
 I clicked yes.  The Mirror browser shows up, I select a mirror.  A
3.0 directory is created, but I got the same error, and when examining
the (new) 3.0 directory, nothing is created inside of it.

Any ideas what this could be caused by?

--j

-- 
Jonathan A. Greenberg, PhD
Assistant Professor
Global Environmental Analysis and Remote Sensing (GEARS) Laboratory
Department of Geography and Geographic Information Science
University of Illinois at Urbana-Champaign
607 South Mathews Avenue, MC 150
Urbana, IL 61801
Phone: 217-300-1924
http://www.geog.illinois.edu/~jgrn/
AIM: jgrn307, MSN: jgrn307 at hotmail.com, Gchat: jgrn307, Skype: jgrn3007