installation problems from an Rstudio server

Dear R People:

I'm not sure if this is an R problem or a Centos 5 problem, but here it
goes:

I'm running Rstudio from a Centos 5 server.  When I try to install packages
from a non-root account, I get the following:

Sys.umask()[1] "22"> install.packages("maps")Installing package into ?/home/erin1/R/x86_64-unknown-linux-gnu-library/3.0?

(as ?lib? is unspecified)trying URL
'http://cran.rstudio.com/src/contrib/maps_2.3-2.tar.gz'Content type
'application/x-gzip' length 1426362 bytes (1.4 Mb)opened
URL==================================================downloaded 1.4 Mb
* installing *source* package ?maps? ...** package ?maps? successfully
unpacked and MD5 sums checked** libs** arch - gcc -std=gnu99 -g -O2
-I/usr/local/include -L/usr/local/lib64  Gmake.c   -o GmakeGmake.c: In
function ?get_lh?:
Gmake.c:111: warning: cast from pointer to integer of different
sizeGmake.c:113: warning: cast from pointer to integer of different
sizeGmake.c: In function ?main?:Gmake.c:211: warning: cast from
pointer to integer of different sizeGmake.c:214: warning: cast from
pointer to integer of different sizeGmake.c:217: warning: cast from
pointer to integer of different sizeGmake.c:219: warning: cast from
pointer to integer of different sizeGmake.c:221: warning: cast from
pointer to integer of different sizeGmake.c:224: warning: cast from
pointer to integer of different sizeGmake.c:227: warning: cast from
pointer to integer of different sizegcc: error trying to exec 'as':
execvp: Permission deniedmake: *** [Gmake] Error 1ERROR: compilation
failed for package ?maps?* removing
?/home/erin1/R/x86_64-unknown-linux-gnu-library/3.0/maps?Warning in
install.packages :
   installation of package ?maps? had non-zero exit status

The downloaded source packages are in
	?/tmp/RtmpIF6S0R/downloaded_packages?> sessionInfo()R version 3.0.1
(2013-05-16)
Platform: x86_64-unknown-linux-gnu (64-bit)

locale:
  [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
LC_TIME=en_US.UTF-8
  [4] LC_COLLATE=en_US.UTF-8     LC_MONETARY=en_US.UTF-8
LC_MESSAGES=en_US.UTF-8
  [7] LC_PAPER=C                 LC_NAME=C
LC_ADDRESS=C
[10] LC_TELEPHONE=C             LC_MEASUREMENT=en_US.UTF-8
LC_IDENTIFICATION=C

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

loaded via a namespace (and not attached):
[1] tools_3.0.1

I've changed the permissions, and updated the umask to 022.

Any help would be much appreciated.

Sincerely,
Erin