After replacing the TDS router with a Tomato powered device TV shows were no longer getting recorded properly on the TDS DVR. The behavior I was seeing was that recorded programs had no video (black screen) and played at an accelerated rate.
TDS TV needs IPTV enabled on the router. There is no specific "iptv" checkbox on Tomato routers, but it can be enabled with two other settings. First it needs the IGMP proxy enabled. This setting can be found under "Advanced" - "Firewall":
Video is sent over multi-cast and it needs to be forwarded to your set top box. This can be accomplished by allowing UDP traffic over multi-cast addresses using iptables. SSH to the router and issue the command:
iptables -A INPUT -p udp -m udp -d 18.104.22.168/4 -j ACCEPT
After these two simple changes, recorded TV works again.