OpenVPN Config file to prevent timeout

I am using OpenVPN with an *.opvn config file under Windows XP to connect to a VPN server. Everything works fine, I connect successfully, but after 2 minutes or so of inactivity my connection dies. Does anyone know if this is a:

• OpenVPN config problem
• Windows problem
• Client network problem
• Server VPN config problem
• Server network problem

I have included my *.opvn config file below:

#OpenVPN Server conf
tls-client
client
dev tun
proto udp
tun-mtu 1400
remote XXX.XXX.XXX.X XXXX
pkcs12 XXXX.p12
cipher BF-CBC
verb 3
ns-cert-type server

I have tried the adding following options to my *.ovpn file with no success:

ping 30
keepalive 10 60

From stackoverflow jakemcgraw

• If possible, have you tried using TCP as a protocol? I've had all sorts of connecting as well as staying connected when using UDP. My config is below and not much different than yours but I can stay connected for hours at a time. I'm using IPCop 1.4.16 with the ZERINA OpenVPN server:

  #OpenVPN Client conf
  tls-client
  client
  dev tun
  proto tcp-client
  tun-mtu 1400
  remote XXX.XXX.XXX.XXX 1194
  pkcs12 XXXX.p12
  cipher BF-CBC
  comp-lzo
  verb 3
  ns-cert-type server
  

  jakemcgraw : I wasn't able to switch to tcp, as the server wasn't configured for this. I ended up solving my problem by having my terminal send a null packet every 20 seconds, which kept the connection alive.
  From dragonmantank