Thaks for your suggestions.
I noticed the backside of the disc tray was not clean so I sprayed some GooGone on a dry wash cloth and cleaned the tray. That did not fix the problem. Removed the printer and My Image Garden from computer and re-installed both. Also installed the Easy PhotoPrint app. Still getting image on discs by about 1/2 inch using both apps. The adjust print option is only plus or minus 0.20 vertical? I wonder where the Advanced Settings dialog window shown in the MIG Guide is - it is not in the MIG app when printing. Another update of software and not updating the user guide that happens in some companies.
The printer is only a few months old and printed only 50 discs with the tray. Really not impressed with disc printing feature if only 50 discs can be printed. The back of the disc tray is scratched various places where I believe the rollers might be. Sounds like a bad mechanical design problem. I will be looking for Canon repair center in my area or apply for new printer or tray under the warranty.