Someone has any idea ? It's the first time I get this problem. At first I taught it was an ARP issue but my ISP told me that he refresh the ARP cache of the router and was still not able to ping the host 188.8.131.52.
I'm happy all is working well for you now. I was thinkg the problem was related to your outside access-list permitting inbound access. You didn't permit any connections to that host you statically mapped. There should be an ACL statement on your outside access-list that looks something like this:
access-list acl_outside permit icmp any 184.108.40.206