DMVPN GRE over IPSEC Packet loss

Question

I have a hub and spoke DMVPN GRE over IPSec topology. We have many sites, over 10, and have a problem on one particular site, just one. First off I want to say that I have replaced the Router and I get the same exact errors. By monitoring the Terminal, I regularly get these messages
%VPN_HW-1-PACKET_ERROR: slot: 0 Packet Encryption/Decryption error, Output Authentication error:srcadr=10.X.X.X,dstadr=10.X.X.X,size=616,handle=0x581A
%CRYPTO-4-RECVD_PKT_MAC_ERR: decrypt: mac verify failed for connection id=1
The tunnel is up, passes data, and always stays up. This router is a Spoke router. The routing protocol being used is EIGRP. When I do a
Show Crypto isakmp sa, it shows the state as being "QM_IDLE" which means it is up.
When I use the "Show Crypto Engine accelerator stat" this is what I get (Attached File)
You can see that there are ppq rx errors, authentication errors, invalid packets, and packets dropped. I know this is not due to mis-configuration because the config is the same exact as other sites that I have which never have any problems. Here is the tunnel interface and the tunnel source interface on the Spoke Router
interface Tunnel111
description **DPN VPN**
bandwidth 1000
ip address 172.31.111.107 255.255.255.0
no ip redirects
no ip unreachables
no ip proxy-arp
ip mtu 1300
ip pim sparse-dense-mode
ip nhrp authentication XXXX
ip nhrp map multicast dynamic
ip nhrp map multicast X.X.X.X
ip nhrp map X.X.X.X X.X.X.X
ip nhrp network-id 100002
ip nhrp holdtime 360
ip nhrp nhs 172.31.111.254
ip route-cache flow
ip tcp adjust-mss 1260
ip summary-address eigrp 100 10.X.X.X 255.255.0.0 5
qos pre-classify
tunnel source GigabitEthernet0/0
tunnel mode gre multipoint
tunnel key XXXX
tunnel protection ipsec profile X.X.X.X
interface GigabitEthernet0/0
description **TO DPNVPN**
ip address 10.X.X.X 255.255.255.0
no ip redirects
no ip unreachables
no ip proxy-arp
ip nbar protocol-discovery
ip pim sparse-dense-mode
ip virtual-reassembly
duplex full
speed 100
no snmp trap link-status
no mop enabled
Is there anything that you can think of that may becausing this, do you think this can be a layer one or two issue? Thanks
Brenden

Answer 1

Have you try to turn off the hardware encryption (no crypto engine accelerator) just to see if it's better. But be careful, cause your CPU% will run much higher, but you only have 10 spokes sites, so it wont be at 100%.
It's better to start troubleshooting by layer 1 then layer 2 when it's possible. Have you ask the site's ISP for packet lost on their side ?