Comment 7 for bug 930491

This appears to be something quite new here where with the current network-manager & network-manager-gnome packages am seeing about 80MB/hr
Downgrading all installed in bulk and things return to normal -

libnm-glib4_0.9.2.0+git201201101813.0b30200-0ubuntu2_i386.deb
libnm-util2_0.9.2.0+git201201101813.0b30200-0ubuntu2_i386.deb
network-manager_0.9.2.0+git201201101813.0b30200-0ubuntu2_i386.deb

libnm-gtk0_0.9.1.90-0ubuntu7_i386.deb
libnm-gtk-common_0.9.1.90-0ubuntu7_all.deb
gir1.2-networkmanager-1.0_0.9.2.0+git201201101813.0b30200-0ubuntu2_i386.deb

network-manager-gnome_0.9.1.90-0ubuntu7_i386.deb
libnm-glib-vpn1_0.9.2.0+git201201101813.0b30200-0ubuntu2_i386.deb

Upgrading back in order the big leak didn't restart until network-manager-gnome was upgraded, then downgrading just network-manager-gnome has again restored things back to normal