I've never used either of those printers but it might help if you told us what you did before that worked.
Try a PDF from Reader or Acrobat.
Thanks for your reaction Peter.
In Indesign I have made a template in which I can load text and images anyway I want. After finishing I made a PDF. The Canon MP970 had a tray where you put the blank disc in. When printing you choose 'printable disc' instead of any kind of paper.
The MP5450 also has a tray but Canon says it only workshop with their software.
Just als they want you to use their ink.
This also answers Bob's question?
So, have you tried printing the PDF and picking their tray and the disk as media? Just 'cause they say something doesn't guarantee it's true.
Peter, thanks for your tip and you're absolutely right.
It worked! The only thing I have to do now is adjust my template so that it is centered on the disc.