error while starting R und XEmacs

["Unternährer Thomas, uth"]

hi all,

I just installed Redhat Fedora (I'm new on unix-like systems) and tried to start R in XEmacs 21.5.b16.

R-version:
platform i686-pc-linux-gnu
arch     i686
os       linux-gnu
system   i686, linux-gnu
status
major    1
minor    8.1
year     2003
month    11
day      21
language R

I installed all XEmacs-Packages (sucessfully, I hope so) and put 
(require 'ess-site) in my init.el.
After typing M-x R the following error-message occurs:

Invalid state: Bogus value for 'default-process-coding-system', nil

Under Windows I work with R and XEmacs without any problems and both typing XEmacs and R in bash works well.

Could anybody give me a hint

Thanks very much (and sorry for my poor english)

Thomas