Comment 28 for bug 68258

I was also getting the error in Feisty:
An unknown error occured code='32' quark='g-exec-error-quark'

For me it started after I resized my swap partition and formatted it using gparted. You can tell if swap is working by running 'sudo swapon -s'. If the swap disk (eg /dev/sda1) appears in the output then it is setup and working. The 'free' command also reports swap usage. If not try turning it on using 'sudo swapon -a'. This didn't work for me because I got:

$ sudo swapon -a
swapon: cannot stat /dev/disk/by-uuid/9be7c290-84e3-4fbb-99b0-727bcead8e8d: No such file or directory

Because of the modifications I did to the swap partition, the uuid had changed, which could be seen running:
$ ls -la /dev/disk/by-uuid
total 0
drwxr-xr-x 2 root root 100 2008-05-06 23:14 .
drwxr-xr-x 5 root root 100 2008-05-06 23:14 ..
lrwxrwxrwx 1 root root 10 2008-05-06 23:14 0031c2e0-d523-49f9-86b8-9f100e6f949e -> ../../sda1
lrwxrwxrwx 1 root root 10 2008-05-06 23:14 86afa7d7-d76d-485a-af40-cb4b7ed87e62 -> ../../sda3
lrwxrwxrwx 1 root root 10 2008-05-06 23:14 fda4423e-e722-4be4-a520-7ec178f192aa -> ../../sda2

sda1 is my swap partition and /etc/fstab had a different uuid for sda1. By editing /etc/fstab to use the uuid reported by /dev/disk/by-uuid and running 'sudo swapon -a' to turn the swap back on, suspend starting working again. Here it is with the swap summary:

$ sudo swapon -s
Filename Type Size Used Priority
/dev/sda1 partition 3903752 0 -1