volatile vs main

[Jim Popovitch <jimpop@gmail.com>]

This is something I've been wondering about for a while, and today I
see a good example with the latest release of Debian 5.0.

I'm using spamassassin from volatile (3.2.5-2+lenny1.1~volatile1) and
the latest version in main is now spamassassin 3.2.5-2+lenny2 which
apt wants to upgrade to.  I know I can pin to the release in volatile,
but is there any harm in letting apt upgrade from a pkg in volatile to
a newer pkg from main, and then later upgrading back to a newer
version that would appear in volatile?

I guess my core question is this:  Are the pkgs (not just SA) released
for main compatible (conf files, paths, DBs, etc) with pkgs released
for volatile?

Thanks,

-Jim P.