Updated my Asus WL-520gU with tomato-NDUSB-1.28.8753-Ext. I got some errors during the restart:
Dec 31 19:00:16 router user.crit dhcpc-event: Error while loading rules. See /etc/iptables.error file.
I also noticed to following in the log file:
Nov 28 11:13:34 router daemon.err miniupnpd: chain upnp not found
So I erased the NVRAM settings and restarted. The router came up with default configuration but was unable to obtain a IP address from the cable modem. I power cycled the cable modem and the router still wasn't able to obtain an address.
I reverted back to .8752-Ext and the router was once again able to get an address from the cable modem after the restart.