$ sudo apt-get upgrade

You might want to run 'apt-get -f install' to correct these.
The following packages have unmet dependencies:
 libldap-2.4-2 : Breaks: libldap-2.4-2:i386 (!= 2.4.28-1.1ubuntu4.2) but 2.4.28-1.1ubuntu4.3 is installed
 libldap-2.4-2:i386 : Breaks: libldap-2.4-2 (!= 2.4.28-1.1ubuntu4.3) but 2.4.28-1.1ubuntu4.2 is installed
E: Unmet dependencies. Try using -f.

$ sudo apt-get -f install

Reading package lists... Done
Building dependency tree
Reading state information... Done
Correcting dependencies... Done
The following packages were automatically installed and are no longer required:
  libunistring0:i386 linux-headers-3.2.0-29 linux-headers-3.2.0-40
  linux-headers-3.2.0-29-generic libgomp1:i386 libcroco3:i386
  linux-headers-3.2.0-40-generic libgettextpo0:i386
Use 'apt-get autoremove' to remove them.
The following extra packages will be installed:
  libldap-2.4-2
The following packages will be upgraded:
  libldap-2.4-2
1 upgraded, 0 newly installed, 0 to remove and 72 not upgraded.
2 not fully installed or removed.
Need to get 0 B/185 kB of archives.
After this operation, 0 B of additional disk space will be used.
Do you want to continue [Y/n]?
dpkg: error processing libldap-2.4-2 (--configure):
 libldap-2.4-2:amd64 2.4.28-1.1ubuntu4.2 cannot be configured because libldap-2.                                                                                        4-2:i386 is in a different version (2.4.28-1.1ubuntu4.3)
dpkg: error processing libldap-2.4-2:i386 (--configure):
 libldap-2.4-2:i386 2.4.28-1.1ubuntu4.3 cannot be configured because libldap-2.4                                                                                        -2:amd64 is in a different version (2.4.28-1.1ubuntu4.2)
Errors were encountered while processing:
 libldap-2.4-2
 libldap-2.4-2:i386
E: Sub-process /usr/bin/dpkg returned an error code (1)