bvop frame counter

On one version of Blender a 2.49 64 bit I get this bvop frame counter on my rendered videos, Xvid Its not on the 32 bit blender 2.49 or any 2.5 build . I can render the same blend file in other build and its not there. I need the 249 for some old blend files. Why is it there and how do I make it go away?