A. SMS 2003 lets you define sites in terms of IP subnets or AD sites. If you define your SMS boundaries by using AD sites instead of subnets, you might receive an error message that says a distribution point for the OS package couldn't be found.
The reason you receive this error is that the OS Deployment Feature Pack installation process can't query AD to find the site for the client. Therefore, the client doesn't fall within the boundary of an SMS site and can't access distribution points (which are restricted to clients in designated SMS sites).
A workaround is to use IP subnets for your SMS boundaries or to install the hotfix that's included in the OS Deployment Feature Pack (but isn't automatically installed). The hotfix is the file sms2003-sp1-kb888311-x86-enu.exe.