I would definitely check and make sure the heads aren't raised. We used to run the XC-540 and would run into that from time to time if it wasn't addressed after printing on something thicker.
Also I would do a test of your bi-directional alignment and make sure that everything lines up the way it should. Something to keep in mind there is that there are actually two bi-directional alignment tools, one that can be accessed by anyone and one in service mode and if they are not both addressed, it can sometimes lead to problems that appear to be overspray. A trick to see if that's the problem without actually changing anything in the service menu of your printer is to set something up as a uni-directional print in versaworks to see if that solves the problem.
If none of that works, do a manual cleaning of the heads and captops. Unfortunately this might also be your Cyan head going out...
Hope this helps!