PXE is working well enough to allow users to boot their computers and log in, but I can't image any computers by using the Ctrl + Alt method.

After holding the keys and selecting option #2 (Interactive mode) I'll get the Zenworks Imaging background, but after a minute I get a DOS-like error saying:

"Could not find the ZENworks Installation Source.
Activating manual setup program."

All my other servers upgraded just fine to 10.2.2, but the imaging server is my only Windows 2003 server.