which package is involed for this bug ?

[r . 3]

Hello, 
I installed wheezy, tried gnome but apparently it does not seem to be very well 
designed for 2 screens. So I am using gnome classic, which is very nice. I have 
a problem with resizing the borders however : the border responsive for click 
and drag is very thin. This problem does not happen with main gnome. 
I would like to file a bug, but what package is involved with this ? 
Thanks, 
William R.