What I did to make it work:
1) "sudo aptitude purge linux-headers-3.0.0-11 linux-headers-3.0.0-11-generic linux-headers-generic"
2) "sudo aptitude install linux-headers-3.0.0-11 linux-headers-3.0.0-11-generic linux-headers-generic" - header files are now correctly installed
3) "sudo aptitude purge virtualbox-guest-dkms virtualbox-guest-utils virtualbox-guest-x11"
4) install guest additions using jockey-gtk
What I did to make it work: 3.0.0-11 linux-headers- 3.0.0-11- generic linux-headers- generic" 3.0.0-11 linux-headers- 3.0.0-11- generic linux-headers- generic" - header files are now correctly installed guest-dkms virtualbox- guest-utils virtualbox- guest-x11"
1) "sudo aptitude purge linux-headers-
2) "sudo aptitude install linux-headers-
3) "sudo aptitude purge virtualbox-
4) install guest additions using jockey-gtk