I sent the vpnc maemo maintainer an email about this. He'll include the fix into the package when he comes around to do it.

I realize this thread is quite old at this point, but I just got my N800 and I'm having a blast with it. Only problem is my campus wireless service requires either VPN access to be able to use the wireless, or 802.1x GTC-PEAP with dynamic WEP, the WEP bit the N800 does not support and I read there is no plan to support it. So that leaves VPN as the only option. I've been struggling with the same problem outlined here, as I just found out. I can connect just fine and browse the internet, but after 5-10 minutes, I can't connect any longer. The VPN connecting remained up, but network connectivity is dead. According to this post, the problem has to do with the routing table. After reading this thread, I checked my routing tables before establishing the vpn, while the vpn is up and internet connectivity is good, and after connectivity drops. I can confirm that the routing table gets changed. So I edited the vpnc-script file according to the thread and the problem persists.
I am using the latest vpnc on diablo. I can provide routing tables if requested.
My question is if this problem was known, why has it not been addressed yet? Am I the only one having this problem? It actually looks like vpnc-script has changed since this thread was posted. The route deletion line is not located at the cited line number as well as the actual contents being slightly different (missing the "DEFAULTGW" after route delete bit)
If this is not a problem in older versions of vpnc (I have 0.5.1 installed), where can I download one? I really need functional vpn connectivity.

Thank you,
--MrAnt--

--edit--
I am able to reestablish connectivity by executing route del default after the other default route is recreated. Any way to auto-delete it? or prevent the auto recreation?