See whether port forwarding helps. The instructions for the DG834G (no instructions for v3 but hopefully these are the same) are here: Port Forwarding for the Netgear DG834G

Make sure to set up a static IP address first - there's a link for this within the link above LW's listening port, port in the 'manual port forward' box & port forwarded within the router's config all need to be the same number.

Otherwise, there are lots of different connection fixes to try here: If LW Will Not Connect

Make sure that LW's being allowed through the McAfee firewall - try removing the current rules for LW & adding them again from scratch: Port Forwarding for the McAfee Security Center