vpn - OpenVPN routing problem

I'm running an OpenVPN server on a VPS running Debian 5, and a OpenVPS client on Ubuntu 11.04 Desktop. I want all outgoing traffic from the client to be tunnelled though the VPN server.

I'm able to initiate a connection from the client to the server, and ping successfully between them, but when I try to access outside IP addresses from the client, I am not successful.

For instance, when pinging google by IP:

ping -n 74.125.91.106

PING 74.125.91.106 (74.125.91.106) 56(84) bytes of data.
^C
--- 74.125.91.106 ping statistics ---
7 packets transmitted, 0 received, 100% packet loss, time 6048ms

On the server side, I can see the ping requests coming thought the tunnel, but no replies going back down:

tcpdump -i tun0
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode

listening on tun0, link-type RAW (Raw IP), capture size 65535 bytes
21:24:59.384736 IP 10.8.0.6 > qy-in-f106.1e100.net: ICMP echo request, id 7537, seq 1,  length 64
21:25:00.391970 IP 10.8.0.6 > qy-in-f106.1e100.net: ICMP echo request, id 7537, seq 2, length 64
21:25:01.400394 IP 10.8.0.6 > qy-in-f106.1e100.net: ICMP echo request, id 7537, seq 3, length 64
21:25:02.408914 IP 10.8.0.6 > qy-in-f106.1e100.net: ICMP echo request, id 7537, seq 4, length 64
21:25:03.416378 IP 10.8.0.6 > qy-in-f106.1e100.net: ICMP echo request, id 7537, seq 5, length 64
21:25:04.424289 IP 10.8.0.6 > qy-in-f106.1e100.net: ICMP echo request, id 7537, seq 6, length 64
21:25:05.431804 IP 10.8.0.6 > qy-in-f106.1e100.net: ICMP echo request, id 7537, seq 7, length 64

I can also see these on the venet0 interface on the server:

tcpdump -i venet0:0 'icmp[icmptype] == icmp-echo or icmp[icmptype] == icmp-echoreply' 
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on venet0:0, link-type LINUX_SLL (Linux cooked), capture size 65535 bytes
21:39:11.397967 IP 10.8.0.6 > qy-in-f106.1e100.net: ICMP echo request, id 7588, seq 1, length 64
21:39:12.407609 IP 10.8.0.6 > qy-in-f106.1e100.net: ICMP echo request, id 7588, seq 2, length 64
21:39:13.415194 IP 10.8.0.6 > qy-in-f106.1e100.net: ICMP echo request, id 7588, seq 3, length 64
21:39:14.423050 IP 10.8.0.6 > qy-in-f106.1e100.net: ICMP echo request, id 7588, seq 4, length 64
21:39:15.431005 IP 10.8.0.6 > qy-in-f106.1e100.net: ICMP echo request, id 7588, seq 5, length 64

21:39:16.439687 IP 10.8.0.6 > qy-in-f106.1e100.net: ICMP echo request, id 7588, seq 6, length 64
21:39:17.446949 IP 10.8.0.6 > qy-in-f106.1e100.net: ICMP echo request, id 7588, seq 7, length 64

I can also ping google successfully from the server.

Any idea what might be causing this?

Server config file:

dev tun
server 10.8.0.0 255.255.255.0
ifconfig-pool-persist ipp.txt
ca ca.crt
cert server.crt
key server.key
dh dh1024.pem
push "route 10.8.0.0 255.255.255.0"
push "redirect-gateway"

comp-lzo
keepalive 10 60
ping-timer-rem
persist-tun
persist-key
group daemon
daemon

Client config file:

remote <<server IP>>
dev tun
comp-lzo
ca ca.crt
cert client1.crt
key client1.key
route-delay 2
route-method exe

redirect-gateway def1
dhcp-option DNS 10.8.0.1
verb 3