not sure if this is related, but gl_subdivide_size have any effect on this? I've only seen the effect of your 1st picture if modifyiny gl_subdivide_size 1024 etc...
warp1scale.vec.x = 1.0f / 1024.0f;
warp1scale.vec.y = 1.0f / 1024.0f;
change that 1024 and see what happens.