Milter-greylist

I am using milter-greylist on 7 mx relays for my domain. I would 
like to perform a rolling upgrade over the next few days for the 
milter-greylist software. I intend to keep my configuraion the same on all 
7 until the software upgrade is done. My question has to do with the 
greylist.conf:peer statement. Currently all 7 sync with each other. When I 
look at the version 4.4.3 greylist.db file that gets spit 
out(greylist.conf:dumpfreq) on my test node, it looks 
like this:


#
# stored tuples
#
# Sender IP     Sender e-mail   Recipient e-mail        Time accepted 
Unsuccessful shortest tarpit
128.118.57.79   <greylist@...>        <jsiegle@...> 
1380547709
#

When I look at the production(V3) db it shows:

# Sender IP     Sender e-mail   Recipient e-mail        Time accepted
206.225.81.15   <henry_stark@...>    <gwc10@...> 1380463166


Will it be safe to upgrade the software on a rolling schedule or must I 
upgrade all the software fairly close together because of these new 
fields? Feel free to point me to a man page. I just couldn't find it.

Thanks,
Jonathan