[gallifrey]% s apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages have been kept back:
  linux-generic linux-headers-generic linux-image-generic
0 upgraded, 0 newly installed, 0 to remove and 3 not upgraded.
[gallifrey]% sudo aptitude upgrade
Resolving dependencies...
Unable to resolve dependencies for the upgrade: no solution found.
Unable to safely resolve dependencies, try running with --full-resolver.
[gallifrey]% sudo aptitude upgrade --full-resolver
The following NEW packages will be installed:
  linux-headers-3.2.0-29{a} linux-headers-3.2.0-29-generic{a}
  linux-image-3.2.0-29-generic
The following packages will be upgraded:
  linux-generic linux-headers-generic linux-image-generic
3 packages upgraded, 3 newly installed, 0 to remove and 0 not upgraded.
Need to get 51.2 MB of archives. After unpacking 217 MB will be used.
Do you want to continue? [Y/n/?]