R help - Sep 2010 - Error: unable to load shared library tcltk.so

Dear R users,
when trying 
> library("tcltk")
i become following error: 
Loading Tcl/Tk interface ... Error : .onLoad failed in
loadNamespace() for 'tcltk', details:
  call: dyn.load(file, DLLpath = DLLpath, ...)
  error: unable to load shared library
'/usr/local/R/R-2.11.1/lib/R/library/tcltk/libs/tcltk.so':
  libtcl8.4.so.0: cannot open shared object file: No such
file or directory
Error: package/namespace load failed for 'tcltk'

Will be very greatful for you help.
> sessionInfo()
R version 2.11.1 (2010-05-31)
i686-pc-linux-gnu

Dr. Alla Bulashevska
Freiburger Center for Data Modeling
Germany