Canon pro4100 print issues

I have a Canon Pro4100 just out of warranty! (as is always the way). Over the past 2 weeks i've been getting lines in the prints(see attached).
I have so far changed ALL the inks!(Angry face!) A new printhead! none 40,000 cleans and head adjustments(not really that many!)
Sometimes it goes away for a few prints and BOOM! its back!
ANY ideas?
I using the same canvas I have used since day 1, genuine inks always, windows OS.
Im ready to burn it now and certainly would never buy another Canon!

 

Hi Paul, i know you made this post a few months ago, but I was curious if you solved this problem. I recently bought the same machine and had a similar problem (horizontal lines) when I used Hahnemule Daguerre canvas for the first time. I did a Paper feed adjustment and the lines no longer appeared. On the touchscreen panel: Maintenance - Paper feed adjustment - Adjust print quality - Auto - Tap paper to adjust.