Cisco ASA 5510 Site to Site VPN with Sonicwall

Question

I am trying to setup a VPN tunnel between a Cisco ASA 5510 (Version 8.2(2)) and Sonicwall TZ200. I got tunnel up and going and I am able to ping the Cisco ASA internal IP from the Sonicwall LAN but nothing else works. When I try to ping a host behind the Cisco ASA from the Sonicwall LAN I get the following message "Asymmetric NAT rules matched for forward and reverse flows; Connection for tcp src outside:10.20.10.x/xxxx dst inside:10.20.2.x/xxxx denied due to NAT reverse path failures" on the ASA
Googling the above error shows issues with version 8.3 and later which looked like the nat commands were changed but the ASA I am working on is still on 8.2 and the other common issue is not adding a NAT exemption. I have double-triple checked that I did add a NAT exception rule from the hosts on the cisco network to the hosts on the Sonicwall network. Seems like I have hit a road block so any help would be appreciated. Thanks
Here are some excertps from the config file (10.20.2.0 behind the cisco and 10.20.10.0 behind the sonicwall)
nat (inside) 0 access-list nonat
access-list nonat extended permit ip 10.20.2.0 255.255.255.0 10.20.10.0 255.255.255.0
access-list outside_1_cryptomap extended permit ip 10.20.2.0 255.255.255.0 10.20.10.0 255.255.255.0
crypto map outside_map 1 match address outside_1_cryptomap
crypto map outside_map 1 set peer x.x.x.x
crypto map outside_map 1 set transform-set ESP-3DES-SHA
crypto map outside_map 65535 ipsec-isakmp dynamic SYSTEM_DEFAULT_CRYPTO_MAP
crypto map outside_map interface outside
crypto isakmp enable outside
crypto isakmp policy 5
authentication pre-share
encryption 3des
hash sha
group 2
lifetime 28800
group-policy SiteToSitePolicy internal
group-policy SiteToSitePolicy attributes
vpn-idle-timeout none
vpn-tunnel-protocol IPSec
split-tunnel-network-list none
tunnel-group x.x.x.x type ipsec-l2l
tunnel-group x.x.x.x general-attributes
default-group-policy SiteToSitePolicy
tunnel-group x.x.x.x ipsec-attributes
pre-shared-key *****
Added few excerpts from config file

Answer 1

Yes inspect icmp is enabled in global_policy
The ping requests time out (The only ping that works is when I ping from the remote side to the ASA internal IP address, no other pings from either side work)
#show crypto isakmp sa
1   IKE Peer: x.x.x.x
    Type    : L2L             Role    : responder
    Rekey   : no              State   : MM_ACTIVE
#show crypto ipsec sa
interface: outside
    Crypto map tag: outside_map, seq num: 1, local addr: x.x.x.x
      access-list outside_2_cryptomap extended permit ip 10.20.2.0 255.255.255.0 10.20.10.0 255.255.255.0
      local ident (addr/mask/prot/port): (10.20.2.0/255.255.255.0/0/0)
      remote ident (addr/mask/prot/port): (10.20.10.0/255.255.255.0/0/0)
      current_peer: y.y.y.y
      #pkts encaps: 0, #pkts encrypt: 0, #pkts digest: 0
      #pkts decaps: 39543, #pkts decrypt: 39543, #pkts verify: 39543
      #pkts compressed: 0, #pkts decompressed: 0
      #pkts not compressed: 0, #pkts comp failed: 0, #pkts decomp failed: 0
      #pre-frag successes: 0, #pre-frag failures: 0, #fragments created: 0
      #PMTUs sent: 0, #PMTUs rcvd: 0, #decapsulated frgs needing reassembly: 0
      #send errors: 0, #recv errors: 0
      local crypto endpt.: x.x.x.x, remote crypto endpt.: y.y.y.y
      path mtu 1500, ipsec overhead 58, media mtu 1500
      current outbound spi: 0ED0F897
      current inbound spi : 596CCE6F
    inbound esp sas:
      spi: 0x596CCE6F (1500302959)
         transform: esp-3des esp-sha-hmac no compression
         in use settings ={L2L, Tunnel, PFS Group 2, }
         slot: 0, conn_id: 50327552, crypto-map: outside_map
         sa timing: remaining key lifetime (sec): 7440
         IV size: 8 bytes
         replay detection support: Y
         Anti replay bitmap:
          0xFFFFFFFF 0xFFFFFFFF
    outbound esp sas:
      spi: 0x0ED0F897 (248576151)
         transform: esp-3des esp-sha-hmac no compression
         in use settings ={L2L, Tunnel, PFS Group 2, }
         slot: 0, conn_id: 50327552, crypto-map: outside_map
         sa timing: remaining key lifetime (sec): 7440
         IV size: 8 bytes
         replay detection support: Y
         Anti replay bitmap:
          0x00000000 0x00000001