logon script not working through group policy

i have a vbs logon script to map printers, i have linked and created a group policy object to an ou containing the computer account i want the gpo applied to.  in the gpo i have applied the script to computer configuration>windows settings>scripts>startup thinking that this would apply the script to that machine and to any user that log onto that machine but it doesnt seem to be working.  even if i apply it to the user configuration>windows settings>scripts it doesnt work.  if i apply the gpo to a OU with user accounts the script works fine.  why is this? how can i get it to apply to the computer?  i have sbs 2003 premium and windows xp pro workstations.