R hangs when loading packages

Hello,

I've recently installed R (version 2.9.0) on my Mac OS (Leopard). I'm  
using the Mac R.app application. Upon start up this works fine,  
however if I try to load several packages the application simply hangs  
(even after leaving it alone for an hour).

Strangely, some applications work fine, others don't. Some examples of  
failures are: R commander, relimp, tcltk. Ultimately, I'm trying to  
get FactoMineR to work with R commander, but when trying to install  
the FactoMineR GUI, which I believe depends on R commander, it also  
hangs. (Note: loading the package FactoMineR itself works fine!)

I've tried to load the packages via the Package Manager, and via the  
command library(rcmdr). I've also tried re-installing the packages,  
and re-installing R entirely. I keep having the same problem.

Any help or suggestions would be greatly appreciated!

Cheers,
Caroline