change login logo bitmap windows 7 x64bit

Hi all,

   I am using OSD sccm 2007 task sequence to deploy windows 7. I am trying to corporate branding and trying to change login icon. So i copy own user.bmp (size 120 x120) to C:\ProgramData\Microsoft\User Account Pictures, it works only when you do start and you can see this bmp, but when you logoff, it just clean icon...

Any help...i thought i can just copy this bmp and should work with 120 size.

thanks in advance....

orion