On some Wifi routers (Sitecom WL-114, WL-141, Siemens SX-551) the following occurs:

1 Connect to WIFI and then from a Windows PC via WinSCP or putty to the N810.
2 if (connection fails)
step 5
else
step 3
3 Wait > 10 minutes
4 Do something in SSH / SCP session
if (Connection lost, cannot reconnect anymore.)
step 5
else
step 2
5 Disconnect N810 and reconnect to same network
6 Goto step 1.

This problem occurs anyway when the N810 has either a DHCP assigned IP address or a fixed one.
In all cases a WPA key is used.
The interesting thing is that OUTbound connection from the N810 (web surfing, MSN, etc. has no rpoblems when the SSH/SCP session freezes.
Other computers in the same network do not have this problem, so it is a problem of the N810.

Is this a N810 firmware bug ?