Comment 6 for bug 1318951

I am also experiencing this bug. But I am using Ubuntu 12.04 LTS. I also have /boot on a FAT32 partition.
This is the output:

alfredo@alfredo-CQ2903EG:~$ sudo apt-get upgrade
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be upgraded:
  linux-image-3.2.0-61-generic
1 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
12 not fully installed or removed.
Need to get 0 B/38.7 MB of archives.
After this operation, 1,024 B of additional disk space will be used.
Do you want to continue [Y/n]? Y
(Reading database ... 541444 files and directories currently installed.)
Preparing to replace linux-image-3.2.0-61-generic 3.2.0-61.92 (using .../linux-image-3.2.0-61-generic_3.2.0-61.93_amd64.deb) ...
Done.
Unpacking replacement linux-image-3.2.0-61-generic ...
dpkg: error processing /var/cache/apt/archives/linux-image-3.2.0-61-generic_3.2.0-61.93_amd64.deb (--unpack):
 unable to make backup link of `./boot/System.map-3.2.0-61-generic' before installing new version: Operation not permitted
dpkg-deb: error: subprocess paste was killed by signal (Broken pipe)
Examining /etc/kernel/postrm.d .
run-parts: executing /etc/kernel/postrm.d/initramfs-tools 3.2.0-61-generic /boot/vmlinuz-3.2.0-61-generic
run-parts: executing /etc/kernel/postrm.d/zz-update-grub 3.2.0-61-generic /boot/vmlinuz-3.2.0-61-generic
Errors were encountered while processing:
 /var/cache/apt/archives/linux-image-3.2.0-61-generic_3.2.0-61.93_amd64.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)