Why isn't Celeron listed as compatible with 925XE?

[jebo_4jc]

On Intel's product page for their 925xe motherboard, it doesn't list any Celerons. Why is this?

http://www.intel.com/design/motherbd/cv2/cv2_proc.htm

I'm trying to build a cheap file server using an Intel-brand motherboard and a Celeron, and the 925xe boards are about the cheapest 775 boards I can find.
http://www.compuvest.com/Description.jsp;jsessionid=ad4tT655IOc6j1Fqk-?iid=318146