aplpack and R2.6.2

I have just moved to R 2.6.2 GUI 1.23 (4932) (4932) on my Intel Mac.

I have tried to load aplpack without success - see below


Loading required package: tcltk
Loading Tcl/Tk interface ... Error in fun(...) : couldn't connect to  
display ":0"
Error : .onLoad failed in 'loadNamespace' for 'tcltk'
Error: package 'tcltk' could not be loaded
Loading required package: tcltk
Loading Tcl/Tk interface ... Error in fun(...) : couldn't connect to  
display ":0"
Error : .onLoad failed in 'loadNamespace' for 'tcltk'
Error: package 'tcltk' could not be loaded

I am a bit confused as on my G4 laptop (R2.4.1) aplpack loads and  
runs fine using the GUI .  I would like to work on my intel Mac so  
any suggestions gratefully recieved( i.e.HELP!)

GJ