sorry fro the delay.
ok it DOES work on a Canon i865
Using photoshop I printed out a image 5267pixels x 1605
Go print with preview
page setup
select landscape
size=custom
click printer
select properties
page setup
printer paer size select custom
custom paper size dialogue pops up
set printing type to "fit to page"
select ok
select ok
select ok
you should then see your preview
select print.
These settings are the one I just used quickly,not set in stone!
here are a couple of pics to prove.
Second one shows you top right what happens when you get your settings wrong.
Hope this helps,good luck
Graham
http://img100.exs.cx/img100/3240/pano11nc.jpg
http://img100.exs.cx/img100/6496/pano25uz.jpg
set to mm width=215 height=584
select page size setr to custom
set to w=210 h=594