N800 testing 'in the field' (around town) has resulted in quite a lot of 'link-local ip address' with the question mark instead of the lollypop on the connection icon. I have not had a single instance at home, with a Trendnet router and about 6 devices connected to it (4 PCs, PAP2, N800).
When connected 'link-local' when in town, viewing the IP Address details on the N800 show:-
ip address: 169.254.63.223
netmask: 255.255.0.0
default router/Primary/Secondary DNS = none
I also struggle with sometimes getting a browser going OK, but cannot send email. My SMTP settings are set to my ISP, which works perfectly from home. Just not when I connect to a free hotspot!