try this:
crypto isakmp profile IKE-PROFILE-2
match identity address n.n.n.n (address of the peer)
crypto ipsec profile PROF1
set transform-set ESP-AES-SHA
set isakmp profile IKE-PROFILE-1
crypto ipsec profile PROF2
set transform-set ESP-AES-SHA
set isakmp profile IKE-PROFILE-2
interface Tunnel0
tunnel protection ipsec profile PROF2
If there is still a problem, then get :
debug crypto isakmp
debug crypto ipsec
debug crypto socket
debug tunnel protection
Start the debugs before the problem occurs.