1. on the main office pix, verify whether there is a route pointing to the router for net 10.x.
2. on the router, verify whether the default route is set to the pix interface; or routes pointing to the pix for remote nets.
3. verify the no-nat and crypto acl on concentrator and remote pixes.
e.g. on the remote pix,
access-list no_nat permit ip 192.168.96.0 255.255.255.0
access-list no_nat permit ip 10.10.10.0 255.255.255.0
access-list l2lvpn permit ip 192.168.96.0 255.255.255.0
access-list l2lvpn permit ip 10.10.10.0 255.255.255.0