Mimiko wrotePlease describe the network infrastructure with IPs including OpenVPN software. From first post you are talking about dd-wrt router then about netgear. I don't see where it resides and on wich router the tracert stops. Also post routing table on each OpenVPN server and client and the computers that a trying to ping, with iptable routes: iptable -L -v, iptables -L -v -t NAT.
dd-wrt is open source software that gets flashed to models of netgear/linksys/dlink/asus/etc that turns the router into a much more powerful router. See
http://www.dd-wrt.com/wiki/index.php/Main_Page.
So while I try to say dd-wrt when referring to router, if it's on a netgear then it's the same thing. The original poster probably meant the same thing... You posted in my thread on the same subject to follow this post. I just posted that I was having the same issue and gave some details too.