R help - Oct 2008 - R 2.7.2 upgrade in Ubuntu, tcltk does not work any more

Hello,

I had no problems running R with tcltk until the recent upgrade to 
R-2.7.2-2gustsy1 (I use Ubuntu 7.10 Gutsy Gibbon). Since the upgrade 
from R-2.7.2-1, I got this error (see hereunder). Obviously, I have now 
a problem with tcltk-related .so files. What should I do? Thanks.

Philippe

phgrosjean at EN-Triton-Ubuntu:~$ R

R version 2.7.2 (2008-08-25)
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ISBN 3-900051-07-0

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 > library(tcltk)
Loading Tcl/Tk interface ... Error in dyn.load(file, DLLpath = DLLpath, 
...) :
   unable to load shared library
'/usr/lib/R/library/tcltk/libs/tcltk.so':
   libtcl8.5.so.0: cannot open shared object file: No such file or directory
Error : .onLoad failed in 'loadNamespace' for 'tcltk'
Error: package/namespace load failed for 'tcltk'
 >
 > R.version
                _
platform       i486-pc-linux-gnu
arch           i486
os             linux-gnu
system         i486, linux-gnu
status
major          2
minor          7.2
year           2008
month          08
day            25
svn rev        46428
language       R
version.string R version 2.7.2 (2008-08-25)
 >