Why don't you save the drivers from a working image, flash the current image and copy the drivers you saved back? That would tell you if it is a driver issue or not.
I can confirm I have already tried this, I can also confirm what judge said....as the receiver wouldn't even boot after putting the drivers from 4.1 onto 4.2 it just got stuck with et8000 on the front lcd , but thankyou for your input. it's driving me nuts now, i've spent more time flashing...adjusting...tweaking than even watching tv.
@Rob
Ive exhausted all your suggestions tonight,i cant see a EDID setting in AV, I've tried every possible video setting on the box and tv including "digital clean view" and "MPEG noise filter" in my samsungs picture menu.
I've rebooted the Xtrend and power cycled my tv between each setting change, I've powered the tv on first then the box and vice versa...
I've tried the scart socket....and even streaming to my tablet and mobile phone the vertical lines persist.
the only way to fix it is to alter the block noise reduction setting in the video enhancer plugin or run the script that I have (which does the same thing).
I'd be more than happy if I could find a way to execute the script when waking the receiver from standby or even being able to assign it to a hotkey on the remote so you didn't have to keep going through the menu's to run it.
the vertical lines show mainly on people's faces, heavy thick lines through the nose, jagged images on cartoons ,at times it's like your looking through a frosted window.