Color problem with canon irc 3200

I started running a job of 20 pages stapled in the corner, full color front and some color pages inside. Ran 20 sets and paper started turning yellow. What may be causing this discoloration?

 

Is it a yellow toner background on the whole sheet?

Press (*) Additional Functions on the keypad
Select Adjustments/Cleaning
Select Auto Gradation Adjustment
Select Full Auto Gradiation Adjustment
This will print and request you scan three sheets in sequence.

Does the full auto grad adjustment improve things?

Also click * then hold 2 and 8 together for a few seconds then quickly hit * again. This will take you into service mode (be very careful in there as you can damage the machine or cause yourself grief.) Click Misc and it will give you the drum yields for each of your drums. What does it show for yellow? (depending on age, what you're printing, etc. we typically get yields up to 180%-250% of life before we start getting backgrounding like this.)

Finally see this post regarding the DCON version of your machine:
http://www.colorprintingforum.com/c...rinting-color-canon-c3200-2926.html#post11338
I wasn't hit with this, but after CanonTechGermany posted this I remember reading this issue a bunch at the time.

 

Thanks Jeff, I did a full auto grad adjustment and it cleared the problem. Ran 400 sets without any problems at all. Thanks for all the help.