I had the same problem with cannon ip1000 in Karmic.
This problem occurs due to wrong rights on /usr/lib/cups/filter/pstocanonbj.
-rwxrwxr-x 1 1000 1000 14084 2005-05-31 13:43 pstocanonbj
Next line solve my problem.
$ sudo chown root:root /usr/lib/cups/filter/pstocanonbj.
You should run this line for your printer.
I had the same problem with cannon ip1000 in Karmic.
This problem occurs due to wrong rights on /usr/lib/ cups/filter/ pstocanonbj.
-rwxrwxr-x 1 1000 1000 14084 2005-05-31 13:43 pstocanonbj
Next line solve my problem.
$ sudo chown root:root /usr/lib/ cups/filter/ pstocanonbj.
You should run this line for your printer.