2D object flickers when it is in high speed in Unity 4.3

Hi, I am working on 2D game in unity4.3. My object get flickers when it is in high speed more speed and more flickering. I adjusted right size of 2D object. I also tested for 3D objects for same speed moving and get same flickering happening on 2D object. I don't know what's the issue behind this. If some one know and faced same issue kindly help me on this. This will be great for me. Thanks in advance.