I have troubles with updating my kernel. I'm running Kubuntu 14.04. uname -r output:

3.13.0-32-generic

I clearly see newer versions in repos with sudo dpkg --list 'linux-image*':

...

linux-headers-3.13.0-40 - Header files related to Linux kernel version 3.13.0

linux-headers-3.13.0-40-generic - Linux kernel headers for version 3.13.0 on 64 bit x86 SMP

linux-headers-3.13.0-40-lowlatency - Linux kernel headers for version 3.13.0 on 64 bit x86 SMP

...

Also, when I was upgrading my system with sudo apt-get dist-upgrade I've noticed the following:

Reading package lists... Done

Building dependency tree       

Reading state information... Done

Calculating upgrade... Done

The following packages were automatically installed and are no longer required:

  linux-headers-3.13.0-34 linux-headers-3.13.0-34-generic

  linux-headers-3.13.0-35 linux-headers-3.13.0-35-generic

  linux-headers-3.13.0-37 linux-headers-3.13.0-37-generic

  linux-headers-3.13.0-39 linux-headers-3.13.0-39-generic

Use 'apt-get autoremove' to remove them.

The following packages will be upgraded:

...

All those kernels are newer than mine also, but for some reason, system decided to keep mine instead.

I had similar problem before. That time I've made some weird tricks with manual installation of header packages, but I think there should be nicer way to get system on track with kernel updating.

Edit:
Here are my /boot contents that clearly show that there are no newer kernels installed: ls /boot

abi-3.13.0-27-generic     config-3.2.0-61-generic       memtest86+.bin                System.map-3.2.0-61-generic

abi-3.13.0-32-generic     grub                          memtest86+.elf                vmlinuz-3.13.0-27-generic

abi-3.2.0-61-generic      initrd.img-3.13.0-27-generic  memtest86+_multiboot.bin      vmlinuz-3.13.0-32-generic

config-3.13.0-27-generic  initrd.img-3.13.0-32-generic  System.map-3.13.0-27-generic  vmlinuz-3.2.0-61-generic

config-3.13.0-32-generic  initrd.img-3.2.0-61-generic   System.map-3.13.0-32-generic