The apt commands of your sda1's 12.04 return the following error:
Another 12.04 user had the same error 4days ago after an update: http://forum.ubuntu-fr.org/viewtopic.php?pid=9525471 He didn't find any solution.
apt-get: error while loading shared libraries: libapt-pkg.so.4.12: cannot open shared object file: No such file or directory
Please try to purge and reinstall GRUB via the command lines method: https://help.ubuntu.com/community/Gr...talling_GRUB_2
Then, if the error persists, i would simply reinstall this way: https://help.ubuntu.com/community/UbuntuReinstallation