It is good that yours works although you need to unplug it and plug it back sometimes. Not sure if to upgrade the firmware will help or not? You USB drive has standby mode? Can you disable it? There...

Your TMG 2010 supports LAN to LAN IPsec VPN? Can you provide the topology? Follow the guide as below to check your settings and post some screenshots of your configuration on ER6020 and TMG 200 here...

You are suggested to report the problem here with your network topology. http://ticket.tp-link.com/index.php?/Tickets/Submit The firmware version is up to date, right?

Portal Authentication. WDS can extend Wi-Fi but it may not be able to pass through it. There are many devices which can extend Wi-Fi signal but the hotspot Wi-Fi environment is more complicated than...

In picture 1, Wi-Fi is connected to modem/router's Wi-Fi or C5's Wi-Fi? Can you turn off modem/router first? And then check ethernet IP and wireless IP obtained from C5. 169.254... is an invalid IP...

As ankhazam said in #10, the bug has been fixed. No worries.