Scrollling Background problem

hi all, I have a background where I want to move continously (I set wrap x = true). I noticed when I test on my Iphone, there is fine line when as it scrolls but there is no line during preview in GS. How do I resolve this?
Comments
option 1
attribute: self position.Y = 720 (you can use = to or less than, or greather than etc)
interpolate attribute: self.poition.Y to -240
duration 20 (or what not) Linear
Rule
Attribute self.position.Y = -240
change attribute self.position.Y to 720
You'll need to add a second actor so it's seamless, or you can use spawn (bad for memory but ok if it's a short level)
option 2 (bad)
Move
direction 270 relative to scene move type additive
speed 75
rule
attribute self.position.y < 400
spawn actor (name of background) layer order BACK OF LAYER or it'll spawn on top your players after a while
direction 0
positions 0 (the rules for move are in the BG)
rule
attribute self.position.y < -300
destroy this actor
I don't recommend option 2 at all...
As shared earlier, this is bug that a line when with on Iphone but looks okie when preview. I can't seemed to get it work with 2 image as the workaround. Anyone can share the tips again? (Tshirtbooth -> can elaborate on the details?)
Appreciate your help on this. Many thanks.
`--Merged to your older thread--tenrdrmer`
Any advise please?