Or also networks that appear open are using MAC filtering or similar to restrict what they'll give DHCP addresses to.

...or they could even be networks with no DHCP server and just static IPs (although it sounds like csoldfield's had problems at coffee shops etc. too)

FWIW, using my two-day-old N800, I can *sometimes* connect to the campus-wide public wireless network at my workplace. When I can connect, I can disconnect and reconnect repeatedly successfully. However, after some time, I get disconnected and then only get the local-link problems. During this time both my PPC6700 and Laptop can connect to and use the wireless network without issue.

It may be chance, but three times now I have success connecting to the public wifi immediately after attempting to connect to our private wifi network (only attempting - I don't think the N800 has everything needed to connect to it).

My Nokias are half a metre from the router when they get the local-link IP, while the Desktop reports 'excellent' signal downstairs. When the N's connect first they get in from the furthest corner of the house (too cold to test in the garden now but that used to be fine too), and the Desktop gets excellent signal again. It is weird...

To followup, the behavior described above is repeatable:

1. Use N800 on open wifi for a while.
2. Eventually link stops working (grr)
3. Attempts to reconnect, gets link-local IP (grr)
4. Repeat (3) endlessly to the same result
5. Manually attempt to connect to private wifi, which then gives me an unable to authenticate error as I haven't set it up properly.
6. An attempt to connect to the open wifi then works.

It would be interesting to replace (5) with an attempt to connect to a different open wifi network and see if that works, but there aren't any here.

I am having this problem too: at home, I can only connect using my anonymous neighbour open connection. When I configure my router (a Belkin G) with no encryption, I always get a local link. I'm of course 1 foot away from my own router and signal is excellent for every other device.
Frenzon "method" doesn't work for me.
Anyone has a workaround?

I just realized yesterday when trying connect to my hotel AP it worked first and then it just got disconnected. Retries to get back access gave always the Link local IP address...

But, it looks in my case that the N800 Bluetooth is giving this problem: It only occurs if Bluetooth is turned on on N800. I noticed this because when I browsed the web I had no problems... not even after long surfing period. But after I opened MaemoMapper, which turns on the Bluetooth automatically, the connection dropped right away. I was not able to get connected or stay connected with MaemoMapper running. Once I closed it and Bluetooth, the WiFi started working again without any issues!

So, could it be that the Bluetooth and the selected channel on the AP is at the same (or too close?) frequency band? They both are at 2.4GHz... but I assume they should not be exactly at the same frequency band?

I made some more experiments and when I changed the WiFi AP channel from 11 to 1 the connection improved. No more disconnects, but I think it still did slow down the connecion, and occasionally caused it to pause downloading. Therefore I'm pretty sure the Bluetooth and WiFi do interfere with each others...

Also both of them are exactly at the same frequency band: 2.40-2.48GHz. Bluetooth should be hopping between the whole band, while WiFi is more constant at the set frequency band.

Anybody seen this behavior in your N800 or 770? If you turn on your bluetooth radio does it degrage your WiFi connection?

I didn't think of that Mara! When I was doing troubleshooting I also changed the channel from 11 to 1. But later I realized there were other problems and figured that after I did get things working again the channel change was moot. But now you have me wondering...

Interesting. BT and WiFi can interfere for sure.
On the other hand, right now I'm streaming music through wi-fi with BT on (I just scanned it from my laptop), and there are no problems. I'm almost 100% certain the wi-fi is on channel 11, unless it was changed recently -- I'll update this posting if so.

I think some routers are just more tolerant. I know my Netgear router had no issues with my 770 (until it crapped out) but my Linksys has (and as noted, other than interference or configuration problems, rebooting the router resolves my recent connection woes). The interference issues seem to have been resolved by the antenna I just added to the router.