we have two ASA 5510s one in 8.4(4) and one in 8.2(5) in a site-to-site VPN setup. All internal traffic is working smoothly.
Site/Subnet A: 126.96.36.199 - local (8.4(4)) Site/Subnet B: 188.8.131.52 - remote (8.2(5)) VPN Users: 184.108.40.206 - assigned by ASA
When you VPN into the network, all traffic hits Site A, and everything on subnet A is accessible.
Site B however, is completely inaccessible for VPN users. All machines on subnet B, the firewall itself, etc... is not reachable by ping or otherwise.
I downgraded to 8.2 and then went back up to 8.4 on the Site A ASA. Site B is now running 8.2(5).
Thank you much in advance and I hope I have been thorough enough.