No WLAN connection to public hotspots possible

[lsmod]

Binary package hint: iw

It is not possible to connect to an WLAN with no encryption!
This is normally the case for any public WLAN Access Point!
So Kubuntu is disqualified for using WLAN with any official Hotspot.

This bug is similar to https://bugs.launchpad.net/ubuntu/+source/linux/+bug/576992
Here it seems that the missing SSID is the problem.
But it is not possible to connect to an Hotspot generally.
I also tried it manually using iwconfig without success.

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: iw 0.9.19~ubuntu1
ProcVersionSignature: Ubuntu 2.6.32-25.44-generic 2.6.32.21+drm33.7
Uname: Linux 2.6.32-25-generic x86_64
NonfreeKernelModules: nvidia
Architecture: amd64
Date: Sat Oct 23 18:27:55 2010
InstallationMedia: Kubuntu 10.04 LTS "Lucid Lynx" - Release amd64 (20100427)
ProcEnviron:
 LANGUAGE=
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: iw

[lsmod (forum+ubuntu)]

There are a few other basic problems in Kubuntu and so i installed Debian Squeeze on a free partition.
In Debian Squeeze it is no problem to connect to a hotspot with no encryption!
It's the same kernel and driver version!

So what have you done with the sources or configuration?

[lsmod (forum+ubuntu)]

This is the working result in Debian Squeeze:

ifconfig
wlan0 Link encap:Ethernet Hardware Adresse 94:0c:6d:8c:ab:c9
          inet Adresse:192.168.1.202 Bcast:192.168.1.255 Maske:255.255.255.0
          inet6-Adresse: fe80::960c:6dff:fe8c:abc9/64 Gültigkeitsbereich:Verbindung
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metrik:1
          RX packets:58 errors:0 dropped:0 overruns:0 frame:0
          TX packets:53 errors:0 dropped:0 overruns:0 carrier:0
          Kollisionen:0 Sendewarteschlangenlänge:1000
          RX bytes:4793 (4.6 KiB) TX bytes:12477 (12.1 KiB)

iwconfig
wlan0 IEEE 802.11bg ESSID:"dd-wrt"
          Mode:Managed Frequency:2.417 GHz Access Point: 00:1E:58:BB:80:CD
          Bit Rate=54 Mb/s Tx-Power=4 dBm
          Retry long limit:7 RTS thr:off Fragment thr:off
          Encryption key:off
          Power Management:on
          Link Quality=70/70 Signal level=-34 dBm
          Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
          Tx excessive retries:0 Invalid misc:0 Missed beacon:0