[CentOS] tabs in emacs fundamental mode?

I'm noticing that under CentOS 6, emacs fundamental mode is no longer
inserting tabs at factor-of-8 tabstops, but rather is doing some 
funky guess-the-intended-tab-distance thing like text mode has done
for a while, currently using three spaces per tab key.

Has anyone tracked down where this was changed and, more to the point,
how to get the old CentOS 5 behavior back?

FWIW, I'm invoking it as "emacs -nw filename".  LANG is "C".

Devin
-- 
He is one of those people who would
be enormously improved by death.			- H. H. Munro