Cisco VPN :: ASA5540 L2L IPSec And Packet Filtering

I need to set up several L2L ipsec tunnels using ASA 5540 (8.2) as a central node and ASA 5505s (8.4) for branch offices. So far I've configured ipsec for the sake of testing between a 5540 and one of 5505, but it blocks ICMP between hosts behind ASAs. Although there's an echo response from 5540's inside interface (172.30.0.1) to echo requests from a host behind ASA 5505 and I see ipsec counters growing. I still can't figure it out despite hurting my eyes with cisco manuals for the relevant ASA software versions.

One thing I couldn't understand in the 8.4 documentation - it says I need ACLs to allow ipsec traffic on outside if I don't NAT/PAT it. Isn't it achieved with "sysopt connection permit-vpn" or do I have to do it manually? I've actually tried adding access-groups for the "in" traffic on outside and those ACLs get hits on both ASAs.
 
The packet-tracer shows some weird DROP at phase 6 on 5505, but I see no rule denying this traffic and the description doesn't mention implicit rules. [code]