Just noticed that if you have assigned static DHCP (with "infinite" lease time) on a given device, if you reboot the router and go to the Device List page, you'll see the following behavour in the sequential order that it happend to me:
1) The Lease time counts down to 0 from a very low number (it was less than 30 seconds when I went to the page)
2) Upon reaching 0, the words "does not expire" (or something to that account) are shown for about 3 seconds or so, which aligns to the setting
3) After a few seconds, the time is set to "0 days, 00:00:00" and stays that way…
Not incorrect in terms of functionality, just very strange to have the above series of steps/events. It should be either item "2" OR "3" I would say…
PS. This is with tomato-E3000USB-NVRAM60K-1.28.7493MIPSR2-Toastman-RT-Ext
but this behaviour was seen with older versions as well.