Yes, Jon told me about the micro banding, which I solved by going to a larger size sheet of Pictorico.
Re the Y channel: After multiple head cleanings, and ignoring the printer for 24 hrs, the nozzle check came out OK. Then, after a few more head cleanings, it was perfect. Now if I leave the printer for a few days unused, or don't do a head cleaning, I'm back were I was: a clogged Y channel. So, I do a multiple head cleanings, leave it for 24 hrs, do a few more cleanings, and it's good again. Seems like an odd process, but with lots of attention it seems to be manageable.
HOWEVER, all these head cleanings is devouring the ink, so I have to regularly fill the carts, do MANY head cleanings after the carts are newly filled (which of course then drains them even more), and then repeat the whole process. Seems like an awful lot of spilt ink, and work, to print my Digital Negatives. Most of my ink seems to be going toward head maintenance instead of prints!