Tile Map Flicker

BlitzMax Forums/BlitzMax Programming/Tile Map Flicker

I have a very large image that I am using as a side scrolling background. Because of its size I have split it into smaller 256*256 images. Then I draw each of the images to the screen in their positions. Each loop I then move all of the tiles slightly to the left thus getting a scrolling background.

The problem is that the vertical "join between the tiles is visible as an imperfection on some screens and a Black flickering vertical line on others.

Has anyone come across this before and if so is there some obvious reason for this that I am missing?

Many thanks,
Tim