This has been an ongoing problem on my RT-N66U since its day one in my possession. I immediately installed tomato on it. I tried Shibby and Toastman builds 3-5 versions back that would include the previous wireless driver version in those builds. I erased NVRAM several times when I was changing the versions and applied configuration changes manually. I even decided to update the CFE bootloader to version 18.104.22.168 using the method described on SmallNetBuider forums. In order to do that I installed the latest non-beta version of the ASUS firmware, then I installed the latest 64K Shibby AIO version of tomato. I observed this problem on ALL versions of tomato I used on this router. I have been using tomato since its first version, when WRT54G was considered a modern router. I did NOT observe this problem on any other router running tomato (my previous router was RT-N16). I did not run the ASUS firmware on my RT-N66U long enough to observe this problem. OK, now the problem itself. Have a look at the attached picture. After a while after reboot, sometimes 2-3 days, sometimes several hours, I see this information in the device list. The quality is above 100, the RSSI's are well above 0 dBm. The 2nd and 3rd devices are webcams that are always on. The first device is my Android 4.2 phone that connected to wireless 15 min ago. The 4th device is an Android 2.3 phone that left the network about 4 hours ago! Its owner left with the phone. Normally such devices disappear from the list after a while (minutes). This is all 2.4 GHz band. The problem is that in this state new wireless devices cannot connect to the router while connected ones stay connected. However, devices still can connect on the 5 GHz band. So, the problem is limited to the 2.4 GHz band. Rebooting the router definitely helps. Later I found out that clicking "Measure Noise floor" button on the Device List page also helps. The RSSI and Quality levels go to normal/reasonable and new devices can connect again. By "new" I mean newly turned on. So it seems that the problem is related to the 2.4 GHz band driver or how tomato interacts with it. There is absolutely nothing about it in the router logs. I googled, searched various forums but never came across any posts describing something similar. A lot of people run tomato on RT-N66U. This problem would bug somebody. Now I am thinking that maybe my router is faulty but its hardware seems to function. This problem happens randomly and disappears after measuring the noise floor or reboot, so I blamed the firmware. But how come nobody else seems to have it? Any thoughts?