[BioC] error message: linux, unable to start device X11

[Mohammad Esad-Djou]

Hello,


I use R 2.2.1 under Linx (Red Hat) and get the following error message:  

> a <- c(1:100)
> b <- c(1:100)
> plot(a,b)
can't find X11 font
Error in X11(display, width, height, pointsize, gamma, colortype, maxcubesize, :
        unable to start device X11


With R 1.9 I did not have an error under Linux. What can I do? 

Thanks,
Mohammad