Problems installing pakages with R.app

I can't uppgrade sources packages with the GUI because I've messages  
like
this:

ERROR: failed to lock directory
'/Library/Frameworks/R.framework/Versions/2.0.1/Resources/library' for
modifying
Try removing
'/Library/Frameworks/R.framework/Versions/2.0.1/Resources/library/ 
00LOCK'

This means that either an installation was aborted w/o cleanup before  
or another installation is already running.

Please note that currently it is not possible in the GUI to  
install/update multiple packages simultaneously if authorizing as root,  
because the root process is spawned independently via Security  
Framework which doesn't give us the child PID and thus the GUI has no  
way of serializing the authorized "system" calls. We are investigating  
ways around this problem. Installing/upgrading as an admin user w/o the  
need to authenticate should work (and individual installs/updates as  
root).

When I use R in the terminal (with sudo), I haven't this problem. I've  
just
notice this warnings:

The entire environment is completely different in Terminal and the GUI,  
thus the warning is probably just trying to tell you that you're  
setting up invalid locales in one of your shell startup scripts. This  
has no effect on the GUI as it's not ran via a shell.

Cheers,
Simon