Stereo Flicker

We have a stereo app (don’t think the fact it is stereo is where it originates from though) . we draw a line on l/r images (GL_BACKLEFT/GL_BACKRIGHT) and then use translatef to seperate these on l/r images. This causes a horizontal flicker/judder/innacuracy. If the translation is 0 there is no flicker. Are there any issues with floating point errors or pixelation problems in this area? Thanks