Seems like you are able to establish the VPN tunnel but sometimes you are not able to send traffic trough the tunnel.
Check MTU issues on Router...
router(config)# crypto ipsec df-bit clear
apply these commands on the inside interface
router(config)# interface Ethernet0
router(config-if)# ip tcp adjust-mss 1300
router(config-if)# ip policy route-map clear-df