From a post I read elsewhere (canon doesn't allow offsite links) you may be able to prevent the PGBK from being called upon if you always specify duplex printing. This is because the printer doesn't want to deal with the possibility of wet PGBK ink ...
The answer I think for me and for other users is ... Functions like this aren't supported in the 64bit driver. A shame. Wouldn't it be a pleasant surprise to get an update that would fix this problem? 64bits have been out a long time.
I.E. Watermark=Background (on MX922). Background can be set in the printer's Page Setup tab, but even though [] Background is checked, the background does not display behind the other printing/images submitted by my programs -- trying with MS Office...