Quick addition to above -
I changed the events in the 'main events group' to-
+ MouseKeyboard: Mouse is over photos
+ System: Always (every tick)
-> TiledBackground1: Set image offset to photos.Value('valx'), photos.Value('valy')
+ MouseKeyboard: On Left Clicked on photos
+ System: Repeat 2 times
-> Canvas: Paste TiledBackground1 into canvas
-> ImageManipulator: Copy image from sprite Canvas
-> ImageManipulator: Copy image to sprite photos
After doing this, i didnt have to double click on the 'photos' to paste in the image.
This doesn't solve the problem (it still pastes to all the sprites) but it stops the 'paste' lag that seems to happen.
Thanks