spamd setup

[R McGlue]

I have two mailhubs running exim (w/ exiscan) +SA+others
I want to let them use each others spamd if the load gets too great on 
any one machine

mailhub1
spamd:
/usr/local/bin/spamd -d -r /logs/spamd.pid -m 7 \
         -i -A 127.0.0.1,mailhub2IP
exiscan:
spamd_address = 127.0.0.1 783 : mailhub2IP 783
=====================================
mailhub2
spamd:
/usr/local/bin/spamd -d -r /logs/spamd.pid -m 7 \
         -i -A 127.0.0.1,mailhub1IP
exiscan:
spamd_address = 127.0.0.1 783 : mailhub1IP 783
Is this the right config??
becuase currently I dont see any activity of either hub on the others log