Wifi : problème de déconnexions

Salut,

J'ai install=E9 Ubuntu Breezy sur un HP Pavillon zt3000. La connexion
wifi a tout de suite fonctionn=E9. Malheureusement, je recontre des
probl=E8mes de d=E9connexion.

Plusieurs fois par jours, la connexion internet est perdue.
G=E9n=E9ralement elle revient rapidement et ce n'est presque pas g=EAnant
mais parfois elle met plusieurs minutes =E0 revenir.

Au d=E9part, j'ai eu tendance =E0 penser que c'=E9tait du aux al=E9as du
sans-fil (probl=E8me de signal, murs porteurs, interf=E9rence etc.) mais
il se trouve que ce m=EAme portable fonctionnait parfaitement sous
windows et que j'ai un autre portable sous windows, que j'utilise en
m=EAme temps et qui utilise la m=EAme connexion et n'a jamais de
probl=E8me.

Comment r=E9gler ce probl=E8me ?
Merci d'avance pour votre aide
Lilian

Pour info, lspci donne
=3D=3D=3D=3D=3D=3D
0000:00:00.0 Host bridge: Intel Corp. 82855PM Processor to I/O
Controller (rev 03)
0000:00:01.0 PCI bridge: Intel Corp. 82855PM Processor to AGP
Controller
(rev 03)
0000:00:1d.0 USB Controller: Intel Corp. 82801DB/DBL/DBM
(ICH4/ICH4-L/ICH4-M) USB UHCI Controller #1 (rev 01)
0000:00:1d.1 USB Controller: Intel Corp. 82801DB/DBL/DBM
(ICH4/ICH4-L/ICH4-M) USB UHCI Controller #2 (rev 01)
0000:00:1d.2 USB Controller: Intel Corp. 82801DB/DBL/DBM
(ICH4/ICH4-L/ICH4-M) USB UHCI Controller #3 (rev 01)
0000:00:1d.7 USB Controller: Intel Corp. 82801DB/DBM (ICH4/ICH4-M) USB
2=2E0 EHCI Controller (rev 01)
0000:00:1e.0 PCI bridge: Intel Corp. 82801 PCI Bridge (rev 81)
0000:00:1f.0 ISA bridge: Intel Corp. 82801DBM LPC Interface Controller
(rev 01)
0000:00:1f.1 IDE interface: Intel Corp. 82801DBM (ICH4) Ultra ATA
Storage Controller (rev 01)
0000:00:1f.3 SMBus: Intel Corp. 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M)
SMBus Controller (rev 01)
0000:00:1f.5 Multimedia audio controller: Intel Corp. 82801DB/DBL/DBM
(ICH4/ICH4-L/ICH4-M) AC'97 Audio Controller (rev 01)
0000:00:1f.6 Modem: Intel Corp. 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M)
AC'97 Modem Controller (rev 01)
0000:01:00.0 VGA compatible controller: ATI Technologies Inc Radeon
R250
Lf [Radeon Mobility 9000 M9] (rev 01)
0000:02:00.0 FireWire (IEEE 1394): VIA Technologies, Inc. IEEE 1394
Host
Controller (rev 80)
0000:02:01.0 Ethernet controller: Realtek Semiconductor Co., Ltd.
RTL-8139/8139C/8139C+ (rev 20)
0000:02:02.0 Network controller: Intel Corp. PRO/Wireless 2200BG (rev
05)
0000:02:04.0 CardBus bridge: ENE Technology Inc CB1410 Cardbus
Controller (rev 01)
=3D=3D=3D=3D=3D=3D

lspci | grep -i wireless
=3D=3D=3D=3D=3D=3D
0000:02:02.0 Network controller: Intel Corp. PRO/Wireless 2200BG (rev
05)
=3D=3D=3D=3D=3D=3D

lsmod
=3D=3D=3D=3D=3D=3D
odule Size Used by
rfcomm 34972 0
l2cap 22404 5 rfcomm
bluetooth 43012 4 rfcomm,l2cap
speedstep_centrino 7380 1
cpufreq_userspace 4444 1
cpufreq_stats 5124 0
freq_table 4484 2 speedstep_centrino,cpufreq_stats
cpufreq_powersave 1920 0
cpufreq_ondemand 5916 0
cpufreq_conservative 6820 0
pcmcia 24584 2
radeon 68352 1
drm 58004 2 radeon
video 16004 0
tc1100_wmi 6916 0
sony_acpi 5516 0
pcc_acpi 11392 0
hotkey 9508 0
dev_acpi 11396 0
i2c_acpi_ec 5760 0
i2c_core 19728 1 i2c_acpi_ec
button 6672 0
battery 9604 0
container 4608 0
ac 4996 0
ipv6 217408 14
af_packet 20232 2
rtc 11832 0
pcspkr 3652 0
irtty_sir 7808 0
sir_dev 17324 1 irtty_sir
irda 159804 2 irtty_sir,sir_dev
crc_ccitt 2176 1 irda
wbsd 15112 0
mmc_core 17924 1 wbsd
yenta_socket 22540 1
rsrc_nonstatic 12032 1 yenta_socket
pcmcia_core 44932 3 pcmcia,yenta_socket,rsrc_nonstatic
ipw2200 92680 0
firmware_class 9472 1 ipw2200
ieee80211 27012 1 ipw2200
ieee80211_crypt 5636 2 ipw2200,ieee80211
ohci1394 30644 0
snd_intel8x0 30144 3
snd_ac97_codec 72188 1 snd_intel8x0
snd_pcm_oss 46368 0
snd_mixer_oss 16128 1 snd_pcm_oss
snd_pcm 78344 4 snd_intel8x0,snd_ac97_codec,snd_pcm_oss
snd_timer 21764 2 snd_pcm
snd 48644 14
snd_intel8x0,snd_ac97_codec,snd_pcm_oss,snd_mixer_oss,snd_pcm,snd_timer
soundcore 9184 1 snd
snd_page_alloc 10120 2 snd_intel8x0,snd_pcm
tpm_atmel 5504 0
tpm_nsc 6528 0
tpm 9504 2 tpm_atmel,tpm_nsc
pci_hotplug 24628 0
intel_agp 21276 1
agpgart 32328 2 drm,intel_agp
nls_cp850 4992 1
vfat 12288 1
fat 46492 1 vfat
nls_utf8 2176 2
ntfs 92016 1
dm_mod 50364 1
joydev 9280 0
tsdev 7616 0
evdev 9088 1
sr_mod 15652 0
sbp2 21128 0
scsi_mod 124872 2 sr_mod,sbp2
ieee1394 90936 2 ohci1394,sbp2
psmouse 26116 0
mousedev 10912 1
parport_pc 31812 1
lp 11460 0
parport 32072 2 parport_pc,lp
md 40656 0
ext3 115976 1
jbd 48536 1 ext3
thermal 13192 0
processor 23100 2 speedstep_centrino,thermal
fan 4740 0
usbhid 30688 0
8139too 23552 0
8139cp 18432 0
mii 5248 2 8139too,8139cp
ehci_hcd 29448 0
uhci_hcd 28048 0
usbcore 104316 4 usbhid,ehci_hcd,uhci_hcd
ide_cd 36996 0
cdrom 33952 2 sr_mod,ide_cd
ide_disk 16128 5
ide_generic 1664 0
piix 9476 1
ide_core 125268 4 ide_cd,ide_disk,ide_generic,piix
unix 24624 845
vesafb 8088 0
capability 5000 0
commoncap 6784 1 capability
vga16fb 12232 1
vgastate 8320 1 vga16fb
softcursor 2432 2 vesafb,vga16fb
cfbimgblt 2944 2 vesafb,vga16fb
cfbfillrect 3840 2 vesafb,vga16fb
cfbcopyarea 4480 2 vesafb,vga16fb
fbcon 34176 72
tileblit 2560 1 fbcon
font 8448 1 fbcon
bitblit 5248 1 fbcon
=3D=3D=3D=3D=3D=3D