Probleme de connection WIFI sous Ubuntu avec Wicd et network manager

Bonjour,

Je suis débutant et j'ai installé UBUNTU il y a 3 jours. Malheureusement j'ai un problème avec ma connection WIFI. Je suis connecté sur un routeur WIFI DLink DI 524.
Tout d'abord avec network Manager, cela reconnaissait la connection puis se deconnectait aprés quelques minutes. J'ai donc installé wicd et là impossible de se connecter, il n'arrivait pas à m'attribuer d'adresse IP; Pire, maintenant, il ne détecte aucun réseau.
J'ai installé Ubuntu en dual boot avec windows 7 et sur windows aucun problème.
Sur Ubuntu, en ce moment je suis sur du filaire.

Mon ordi est un Aspire 7540g avec une carte Acer Nplify.

Voici les infos:

cat /etc/lsb-release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=9.10
DISTRIB_CODENAME=karmic
DISTRIB_DESCRIPTION="Ubuntu 9.10"

lsusb
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 005 Device 002: ID 0d62:a100 Darfon Electronics Corp. Benq Mouse
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 003: ID 04f2:b044 Chicony Electronics Co., Ltd
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

lspci
00:00.0 Host bridge: Advanced Micro Devices [AMD] RS780 Host Bridge Alternate
00:02.0 PCI bridge: Advanced Micro Devices [AMD] RS780 PCI to PCI bridge (ext gfx port 0)
00:04.0 PCI bridge: Advanced Micro Devices [AMD] RS780 PCI to PCI bridge (PCIE port 0)
00:05.0 PCI bridge: Advanced Micro Devices [AMD] RS780 PCI to PCI bridge (PCIE port 1)
00:11.0 SATA controller: ATI Technologies Inc SB700/SB800 SATA Controller [AHCI mode]
00:12.0 USB Controller: ATI Technologies Inc SB700/SB800 USB OHCI0 Controller
00:12.1 USB Controller: ATI Technologies Inc SB700 USB OHCI1 Controller
00:12.2 USB Controller: ATI Technologies Inc SB700/SB800 USB EHCI Controller
00:13.0 USB Controller: ATI Technologies Inc SB700/SB800 USB OHCI0 Controller
00:13.1 USB Controller: ATI Technologies Inc SB700 USB OHCI1 Controller
00:13.2 USB Controller: ATI Technologies Inc SB700/SB800 USB EHCI Controller
00:14.0 SMBus: ATI Technologies Inc SBx00 SMBus Controller (rev 3c)
00:14.2 Audio device: ATI Technologies Inc SBx00 Azalia (Intel HDA)
00:14.3 ISA bridge: ATI Technologies Inc SB700/SB800 LPC host controller
00:14.4 PCI bridge: ATI Technologies Inc SBx00 PCI to PCI Bridge
00:18.0 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] HyperTransport Configuration
00:18.1 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Address Map
00:18.2 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] DRAM Controller
00:18.3 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Miscellaneous Control
00:18.4 Host bridge: Advanced Micro Devices [AMD] K10 [Opteron, Athlon64, Sempron] Link Control
02:00.0 VGA compatible controller: ATI Technologies Inc Device 68c1
02:00.1 Audio device: ATI Technologies Inc Device aa60
03:00.0 Ethernet controller: Broadcom Corporation NetLink BCM5784M Gigabit Ethernet PCIe (rev 10)
06:00.0 Network controller: Atheros Communications Inc. AR928X Wireless Network Adapter (PCI-Express) (rev ff)

lspci -nn | grep -i net
03:00.0 Ethernet controller [0200]: Broadcom Corporation NetLink BCM5784M Gigabit Ethernet PCIe [14e4:1698] (rev 10)
06:00.0 Network controller [0280]: Atheros Communications Inc. AR928X Wireless Network Adapter (PCI-Express) [168c:002a] (rev ff)

sudo lshw -C network
[sudo] password for paulina:
*-network
description: Ethernet interface
product: NetLink BCM5784M Gigabit Ethernet PCIe
vendor: Broadcom Corporation
physical id: 0
bus info: pci@0000:03:00.0
logical name: eth0
version: 10
serial: 00:26:2d:7a:28:6e
size: 100MB/s
capacity: 1GB/s
width: 64 bits
clock: 33MHz
capabilities: pm vpd msi pciexpress bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=tg3 driverversion=3.99 duplex=full firmware=sb v2.19 ip=192.168.1.142 latency=0 link=yes multicast=yes port=twisted pair speed=100MB/s
resources: irq:28 memory:f0200000-f020ffff
*-generic DISABLED
description: Wireless interface
product: Illegal Vendor ID
vendor: Illegal Vendor ID
physical id: 0
bus info: pci@0000:06:00.0
logical name: wmaster0
version: ff
serial: c4:17:fe:25:7e:3e
width: 32 bits
clock: 66MHz
capabilities: bus_master vga_palette cap_list logical ethernet physical wireless
configuration: broadcast=yes driver=ath9k latency=255 maxlatency=255 mingnt=255 multicast=yes wireless=IEEE 802.11bgn
resources: irq:17 memory:f0300000-f030ffff

lsmod
Module Size Used by
isofs 31620 0
udf 80900 1
crc_itu_t 1852 1 udf
binfmt_misc 8356 1
joydev 10240 0
ppdev 6688 0
snd_hda_codec_atihdmi 3356 1
snd_hda_codec_realtek 203328 1
arc4 1660 2
ecb 2524 2
snd_seq_dummy 2656 0
snd_seq_oss 28576 0
snd_hda_intel 26920 2
snd_hda_codec 75708 3 snd_hda_codec_atihdmi,snd_hda_codec_realtek,snd_hda_intel
snd_hwdep 7200 1 snd_hda_codec
snd_seq_midi 6464 0
snd_rawmidi 22176 1 snd_seq_midi
snd_seq_midi_event 6940 2 snd_seq_oss,snd_seq_midi
snd_seq 50224 6 snd_seq_dummy,snd_seq_oss,snd_seq_midi,snd_seq_midi_event
snd_pcm_oss 37920 0
snd_mixer_oss 16028 1 snd_pcm_oss
snd_seq_device 6920 5 snd_seq_dummy,snd_seq_oss,snd_seq_midi,snd_rawmidi,snd_seq
snd_pcm 75296 3 snd_hda_intel,snd_hda_codec,snd_pcm_oss
uvcvideo 59080 0
videodev 36736 1 uvcvideo
v4l1_compat 14336 2 uvcvideo,videodev
psmouse 56500 0
serio_raw 5280 0
iptable_filter 3100 0
ath9k 258744 0
mac80211 181140 1 ath9k
ath 8060 1 ath9k
ip_tables 11692 1 iptable_filter
x_tables 16544 1 ip_tables
snd_timer 22276 2 snd_seq,snd_pcm
i2c_piix4 9932 0
snd 59204 16 snd_hda_codec_realtek,snd_seq_oss,snd_hda_intel,snd_hda_codec,snd_hwdep,snd_rawmidi,snd_seq,snd_pcm_oss,snd_mixer_oss,snd_seq_device,snd_pcm,snd_timer
soundcore 7264 1 snd
snd_page_alloc 9156 2 snd_hda_intel,snd_pcm
acer_wmi 15936 0
led_class 4096 2 ath9k,acer_wmi
cfg80211 93052 3 ath9k,mac80211,ath
lp 8964 0
parport 35340 2 ppdev,lp
usbhid 38208 0
video 19380 0
output 2780 1 video
tg3 109600 0

iwconfig
lo no wireless extensions.

eth0 no wireless extensions.

wmaster0 no wireless extensions.

wlan0 IEEE 802.11bgn ESSID:"ACOSTA WiFi"
Mode:Managed Frequency:2.437 GHz Access Point: Not-Associated
Tx-Power=20 dBm
Retry long limit:7 RTS thr ff Fragment thr ff
Power Management n
Link Quality:0 Signal level:0 Noise level:0
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0

ifconfig
eth0 Link encap:Ethernet HWaddr 00:26:2d:7a:28:6e
inet adr:192.168.1.142 Bcast:192.168.1.255 Masque:255.255.255.0
adr inet6: fe80:2dff286e/64 Scope:Lien
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Packets reçus:50021 erreurs:0 :0 overruns:0 frame:0
TX packets:39447 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 lg file transmission:1000
Octets reçus:61779344 (61.7 MB) Octets transmis:12810483 (12.8 MB)
Interruption:16

lo Link encap:Boucle locale
inet adr:127.0.0.1 Masque:255.0.0.0
adr inet6: ::1/128 Scope:Hôte
UP LOOPBACK RUNNING MTU:16436 Metric:1
Packets reçus:0 erreurs:0 :0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 lg file transmission:0
Octets reçus:0 (0.0 B) Octets transmis:0 (0.0 B)

sudo iwlist scan
[sudo] password for paulina:
lo Interface doesn't support scanning.

eth0 Interface doesn't support scanning.

wmaster0 Interface doesn't support scanning.

wlan0 Interface doesn't support scanning : Network is down

uname -r -m
2.6.31-20-generic i686

cat /etc/network/interfaces
auto lo
iface lo inet loopback



Merci d'avance