Affinity doesn't get set in Win7

I can't seem to get proxyuser.exe to run with a preassigned affinity setting under Win7.  I can manually set it via the task manager, but batch calls don't seem to work.

start "TileProxy" /AFFINITY 0X04 /REALTIME "C:\...\TILEPROXY\PROXYUSER.EXE"

That's a sample of my call.  Of course the '...' is replaced with the full path name.

It still comes up using any core and with a priority of "Above Normal".