PIXMA MX922 suddenly won't print duplex

[rdoty1]

I have been printing booklet mode and duplex with my MX922 for several months and all of a sudden it will not print duplex.  I have tried everything including above but still no luck - except wasting a lot of paper and ink.  Any advice?

[rdoty1]

(additional info).  If I check "automatic" duplex I get a message that says "A paper size that is not supported by the automatic duplex printing function is selected" and to unselect the automatic function.  If I unselect then I get a "manual" duplex notice requiring me to print both sides individually.