The cd/dvd tray is not set correctly.

I hope this will help you :)
* Green Power light flashes- The printer is receiving a print job, replacing an ink cartridge, charging ink, or cleaning the print head.
* RED paper light is On- If the CD/DVD try guide is open, close the CD/DVD tray guide, load paper, then press the paper button. Your paper ran out or multiple sheets loaded at the same time . Load paper and press the paper butoon to resume printing.
* RED paper light flashes- Paper is jammed in the printer. Press the paper button to eject the jammed paper. If the light is still flashing , open the cover and remove all paper, including any jammed or torn pieces. Then reload paper and press the paper button to continue printing.
* RED Ink Light Flashes - One or more cartridges are low on ink. Check the message that appears on your screen to determine which cartridge is low, or follow the instructions in " Checking the Ink Supply". Make sure you have a replacement cartridge.
* RED Ink Light is ON- One or more cartridges are out of ink or not installed. If you have just installed a new cartridge, it may be incomaptible with the printer or incorrectly installed. Reinstall it or replace it with the correct cartridge
* RED Ink and RED paper lights flash alternately- The CD/DVD tray guide was left open when you turned on the printer or when printing on paper. Just simply close it/
* Green Power Light is Off; RED paperand RED Ink Lights flashing- Paper may be blocking movement of the print head. Turn off the printer, then open the cover and remove any jammed paper or other foreign objects. Turn the printer back on again. Or it may have an internal error. Turn off the printer, wait a few seconds, then turn it on again.

This printer have a sensor to remind the user when using a wrong paper size.

If you still using a paper that not the same with your software settings, it's still reminds you.

I solve this promblem by after print my works I just press "Cancel Jobs" button to clear a data.

Good luck.

I am trying to print on DVD with Canon MP810 but the image won't line up - seems to be taking the tray too far in and printing some of the image on the F tray! Help.... it's driving me nuts

Lightly sand paper the underside of the CD/DVD tray, it is probably just slipping.

Here is the problem... Because the printer has more then one feed, your program(i.e. MS word) is selecting the CD tray by default.

The solution in MS Word is to go to the Envelopes and Settings then select OPTIONS.

There should be a option in here to select the other tray.

Well... here it is :

The POWER Lamp Flashes Orange An error has occurred in the printer. The number of flashes indicates the type of error, as outlined below. Check the cause and take the appropriate action.
When a printer error occurs, the POWER lamp flashes. The number of flashes indicates the type of error that has occurred. Count the flashes and take the appropriate action to correct the error.
Two flashes: Printer is out of paper /Paper does not feed
Reload paper to the sheet feeder or cassette and press the RESUME button.
Three flashes: Paper jam/Paper output tray is closed
If paper is jammed, remove the jammed paper, reload paper in the printer, and then press the RESUME button. If the paper output tray is closed, open it.
See Paper Jams
Four flashes: Empty ink tank
Press the RESUME button to resume printing with an empty ink tank. Replace it with a new ink tank immediately after the printing. It may damage the printer if you continue printing with an empty ink tank.
Five flashes: Print head not installed/Print head not installed correctly/Print head is defective
Install the Print Head. If the Print Head is already installed, remove the Print Head and check the electrical contacts for foreign matter, then reinstall.
After reinstalling the Print Head, you may need to realign it.
If this error still remains, the Print Head may be damaged. Contact a Canon service representative.
Six flashes: Inner cover error
To print on paper:
Close the inner cover. Then press the RESUME button to start printing.
Do not move or close the inner cover during printing. It may damage the printer.
Seven flashes: The CD-R or DVD-R is not set on the CD-R tray
Reset the CD-R tray feeder with a CD-R tray containing a CD-R or DVD-R, and then press the RESUME button. Printing will resume.
This function only works with models that support CD-R printing.
Eight flashes: Waste ink absorber almost full
The printer has a built-in waste ink absorber for the ink used during print head cleaning. Eight flashes indicates that the waste ink absorber is nearly full. Press the RESUME button to cancel the error so you can continue printing. Before the waste ink absorber becomes completely full, contact a Canon service representative.
Important
Canon recommends that you call for service as soon as this error occurs. Once the waste ink absorber becomes completely full, printing will no longer be possible.
Nine flashes: A specified period of time has lapsed without receiving no response from the digital camera / The digital camera or digital video camcorder connected is not compatible with this printer
Disconnect the camera cable, press the printer's RESUME button and reconnect the cable.
If the error is still not solved, there is a possibility that you are using a digital camera or digital video camcorder that is not supported by this printer. Use a digital camera or digital video camcorder compatible with this printer.
Ten Flashes: Cannot print on both sides of the page
The size of paper may not be compatible with automatic duplex printing. For information on the size of paper compatible with auto duplex printing, see "Automatically Printing on Both Sides of the Page." Pressing the RESUME button will discharge the paper, and restart printing from the front side of the next paper. The reverse side will not be printed when an error occurs.
Eleven flashes: Cannot perform automatic print head alignment correctly
Possible causes are as follows:
A4 or Letter-sized paper is not loaded on the sheet feeder.
Ink has run out or ink tanks are not installed correctly.
See Ensure that the ink tank is installed properly.
Ink level is low.
Print Head nozzles are clogged.
Press the RESUME button.
For information on how to print a nozzle check pattern, see "Printing the Nozzle Check Pattern."
The paper output slot has been exposed to a strong light source preventing correct print head alignment.
Press the RESUME button to resolve the error. Align the printer so the paper output slot will not be exposed directly to a strong light source.
After carrying out the above measures, if the problem continues after aligning the print head again, press the RESUME button to resolve the error, and then perform manual print head alignment. For details on manual print head alignment, see "Aligning the Print Head."
POWER lamp flashes alternate green and orange:
An error that requires contacting a Canon service representative may have occurred.
Disconnect the printer cable from the printer, and then turn the printer off and unplug the printer from the power supply. Plug the printer back in and turn the printer back on after leaving it for a while.
If the problem remains, contact a Canon service representative.

Hi Chillyslade,

Try this..

Close the CD/DVD guide, then press the maintenance button.
If the CD/DVD tray is inserted, remove the CD/DVD tray, then close the CD/DVD guide

Hope this works, kindly let me know by providing your valuable rating.

Thanks,
Robosoft.

Yes I had a similar problem and in fact returned my printer for a replacement. You need clearance as the CD tray emerges some 2.5 to 3 inches behind the printer. If the tray hits an obstacle it is unable to correctly line up for printing and the trat is rejected

Those generic refills are not worth i, plus they may void the warranty. Try removing them and cleaning the little circuit board sensor. Make sure leaked ink hasnt covered them.

The answer to this is to insert the cd tray then click to print then when its about to print put some light pressure with your fingers and you will see the tray will go in and it willl print just fine does it with mine all the time so thats what i do to rememedy the problem...good luck