I followed the guide to deploy XP to an OptiPlex 780. The deployment completes, but a few of the devices show up in the Device Manager as invalid. If I select Update Driver, the driver is found automatically and is installed. From what I can tell it looks like Configmanager is pushing the drivers to the Opti 780, but the drivers are not being installed/applied. I tried both the auto apply and apply driver package task sequence. Same result.

Any Ideas?

try using the command for a command task:

rundll32.exe Syssetup.dll,UpdatePnpDeviceDrivers