Seam appears when tiling

[kofight]

hi,
       I'm working on a three match game, use some NGUI sprites to create the game area's background.
       There's no seams when I put it still, works perfectly as attachment 1

       But when I try to tween the game area's position(I put all grids under a single transform parent), sometime it shows seam like attachment 2.
       
       Some information might be helpful:
       I can't see the seam in scene view in UnityEditor.
       If I change to scene view in UnityEditor and change back to game view, the seam disappears.
       On ios device, I can see the seam, but when I switch to desktop and switch back, the seam disappears.

       Seem's like I just need another Refresh to correct the seam, but I don't know how.
       

[AlexSudnikov]

Looks weird.

If there were seams in a still stage , it could've been related to close borders proximity but in your case it seems to be different.
Although you can try to increase canvas size of your icons , so that there were more space in image's edges.

[ArenMook]

I'm not sure what this would be caused by in your case, but I'd suggest you do a tiled sprite for the background, not make it out of multiple sprites.