The packages causing this were from https://launchpad.net/~dnjl/+archive/virtualization/: virtualbox* version 4.1.0-dfsg-1ubuntu0~dnjl0~natty0
The packages causing this were from https:/ /launchpad. net/~dnjl/ +archive/ virtualization/: virtualbox* version 4.1.0-dfsg- 1ubuntu0~ dnjl0~natty0