Wireless n disconnects my tv

[Hjalle]

I have a sony bravia tv (nx723) capable of wireless n (2.4ghz). With my old router tp-link tl-MR3420, everything works fine with wireleess n.
But with my n56u it doesn't work so fine.

When I change to only n in the router the tv will connect and all will work fine. But when I start the tv the next day the tv says it is connected but cant get access to the network anymore.
If i change the router to g all will work fine.
If I change the router to g/n (both g and n) the tv have access to the network but it will be slow (<1mb/s).
To be more clearly:

802.11g - TV connects and can access the network. Good downstream (ie watch Youtube HD and stream HD from NAS)
802.11g/n - TV connects and can access the network at first with good downstream. 1 day later the TV can still access the network but the downstream is bad. Can't watch HD content.
802.11n (only, Greenfield enabled) - TV connects and can access the network at first with good downstream. 1 day later the TV connects to wireless (it get an IP-address) but can't access network at all.

I have tested many firmware, also Padavan but no luck.
Any ideas?

 

[Guz]

Update the firmware of the TV?!?!?!?

 

[Hjalle]

Update the firmware of the TV?!?!?!?

Have the latest firmware already.
All is working fine until I shut down the tv and start it again. It connect but there are some problems and the speed is terrible. Something wrong with DHCP? I have tried to assign the tv an own ip-address but no luck.
Other routers work fine. But also the phones connected to the router (iphone & htc) are fine.

Do you have some ideas of which settings I might change?

I have noticed with my iphone that there is some delay to connect to the router when the phone is unlocked. With my airport extreme there wasn't so much delay. Any thoughts?

 

[Hjalle]

Have played around with the settings and I found a solution.
It is the network key rotation interval. But it doesnt help if i set it to 0. So i have set it to max 2592000s.
Is it a bug in the router or is it the tv?
i dont know how this network key rotation works, but i thought it wasnt used when you have wpa2 psk.