Ubuntu – Can’t run apt-get upgrade – Getting stuck in reading logs

I'm trying to run an apt-get upgrade (after first running apt-get update), but my Ubuntu 12.04 server isn't completeing the upgrade process. It asks me if I want to upgrade 6 available packages, then it says it's reading the logs, and then I believe nano opens and shows the following:

Get:1 Changelog for base-files (http://changelogs.ubuntu.com/changelogs/pool/main/b/base-files/base-files_6.5ubuntu6.4/changelog) [78.4 kB]
base-files (6.5ubuntu6.4) precise; urgency=low

• Mark /etc/os-release as a conffile, and migrate it in the preinst
  for the benefit of people who tested the previous precise version

  — Adam Conrad Tue, 23 Oct 2012 22:52:07 +0100

base-files (6.5ubuntu6.3) precise-proposed; urgency=low

• Install /etc/os-release. LP: #947236.

  — Matthias Klose Tue, 09 Oct 2012 19:36:33 +0200

Get:1 Changelog for libudev0 (http://changelogs.ubuntu.com/changelogs/pool/main/u/udev/udev_175-0ubuntu9.2/changelog) [156 kB]
udev (175-0ubuntu9.2) precise-proposed; urgency=low

• Add persistent-input-symlinks-iface00.patch: Fix persistent input symlinks
  for interface 00. Thanks to a7x for pointing this out! (LP: #1057824)

  — Martin Pitt Thu, 11 Oct 2012 09:17:05 +0200

/tmp/tmpU6dn1w (END)

I can only exit out of that using control-c, and once I'm back where I can enter commands I can type text but nothing shows on the screen. The commands work, I just can't see anything. Once I end the SSH connection and then re-connect it shows I have those same 6 packages available.

The 6 packages it shows that are available are:

base-files 6.5ubuntu6.4
libgudev-1.0-0 1:175-0ubuntu9.2
libgudev-1.0-0:i386 1:175-0ubuntu9.2
libudev0 175-0ubuntu9.2
libudev0:i386 175-0ubuntu9.2
udev 175-0ubuntu9.2

Any ideas on why the upgrade isn't working properly?