I'm having a problem with my router connecting to my N900 - general browsing is fine (I'm posting this connected to the router), but any apps will not download data.
I first noticed it with ForecaWeather when it stopped downloading updates, so I uninstalled that and replaced it with OMWeather, but still had the same problem.
While trying to figure out the problem I tried out my 3G connection and everything worked fine. So, I tried it out with other apps and it was exactly the same - email, refreshing Extras, basically anything that downloads data, works fine over my Cellular connection, but doesn't work at all with my router. So, my question is just - has this happened to anyone else? Are there any settings I need to look at on the router?
As a bit of background info, the router has WPA security, it's not MAC restricted, and it works ok with everything else connected to it; a laptop, desktop, netbook, 2 Symbian phones and an Xbox

I have noticed a similar thing with an older DLink router though my new one is fine. the same issue occured with an E61 when 802.11b/g/n mode enabled, when set to b/g only it was fine.

I had the same problem until changing the wifi radio to 100mW and medium for power saving. Connection issues went away.

I have two N900's right now and both have the same issue with my G/N dual band Netgear router.

Sending the second one back this week (was supposed to replace my current N900, but same issues PLUS the second one reboots randomly). Definite device issue, since no apps were install to the second one. Just what came with it.

Sorry to bump an old thread, but I found the answer to this from a post by fnordianslip -

Hopefully this will be useful to anybody having the same problems I did. And thanks fnordianslip, you may have saved my sanity!

I had some issues with wifi, too. I disabled WPA, and then it started working again. Now my Access Point is open, till i find a good solution. Dont know if its a router issue or a N900 one.

maybe a firewall port blocking problem on your router?

does it have a firewall log that you can look at when the app is attempting to get data?

Gunni, have you tried turning WPA back on?
I saw a similar thing myself, but it went away after some combination of reboots (device and router) and deleting and adding the access point to the list.

Like Ronan said, use the DNS settings from your modem not your router.