Using initscripts-5.07-1, and no change in device configuration since redhat 6.2, I have eth0 set to be enabled on bootup. However, only lo gets activated, not eth0. Perhaps something screwy in the egrep lines of /etc/rc.d/init.d/network? I couldn't trace it down myself.
I figured out what's causing this - seems like a little typo in the logic there. Lines 63 and 65 have to be switched, or else the opposite of the intended action will happen. Also, it seems as though adding the 'grep -v "^#"' to there didn't make a difference with stopping lines that start with # to be ignored, but that's not my problem.
Fixed in 5.08 and later. (yes, the grep was in the wrong place.)
*** Bug 100866 has been marked as a duplicate of this bug. ***