I have this problem:
At home and at another home there are WPA2 WiFi hotspots. After reboot my N900 connects automatically to the stronger WLAN, when I change the house the N900 changes the WLAN, automagically...

But after some hours, connection is lost, and I cannot reconnect using the status bar tool. When I try (both WLANs are shown in the list), after 15 or so seconds it tells me there were a "network problem" and it asks if it should try again. When I say yes, same problem occurs again.
Only chance to get into the WLAN again is to reboot my N900 :-( or is there another way? What is the problem?

Do you have channels 12 & 13 and/ or "auto" enabled on your router?

How long is your DHCP lease time?

Sounds like https://bugs.maemo.org/show_bug.cgi?id=6416 which is fixed internally already. Fix will be available in a future update.

no my WLAN device uses fixed channel 1. I don't know about the DHCP lease time though. It is an Apple Airport Express or Time Capsule, whatever snaps it first.
I also thought of DHCP problems. How could I force a stop/reconnect sequence in Maemo? Something like "/etc/init.d/networking restart" on a regular Linux box?

okay it is a known bug, already fixed internally, and the fix will be included into the next public firmware release. Nice.
Thanks Andre Klapper for the link into bugzilla.