Hello all,
Unfortunately, the very good guide at http://www.debiantutorials.org/content/view/153/213/ didn't work for me.

I have a hp notebook with a turion64 processor running debian-amd64 testing. I use a d-link dsl-g604t as a modem/router which is one foot away from my notebook. My wifi card is the Broadcom Corporation BCM4318 [AirForce One 54g] 802.11g Wireless LAN Controller (rev 02) (copy-paste from lspci).
I even built and installed a custom linux kernel (2.6.20.4 ver) but to no avail.
Here's the relevant info from dmesg:
bcm43xx: Chip ID 0x4318, rev 0x2
bcm43xx: Number of cores: 4
bcm43xx: Core 0: ID 0x800, rev 0xd, vendor 0x4243
bcm43xx: Core 1: ID 0x812, rev 0x9, vendor 0x4243
bcm43xx: Core 2: ID 0x804, rev 0xc, vendor 0x4243
bcm43xx: Core 3: ID 0x80d, rev 0x7, vendor 0x4243
bcm43xx: PHY connected
bcm43xx: Detected PHY: Version: 3, Type 2, Revision 7
bcm43xx: Detected Radio: ID: 8205017f (Manuf: 17f Ver: 2050 Rev:

bcm43xx: Radio turned off
bcm43xx: Radio turned off
...
ieee80211_crypt: registered algorithm 'WEP'
bcm43xx: set security called, .active_key = 0, .level = 1, .enabled = 1, .encrypt = 1
bcm43xx: PHY connected
bcm43xx: Microcode rev 0x127, pl 0xe (2005-04-18 02:36:27)
bcm43xx: Radio turned on
bcm43xx: ASSERTION FAILED (radio_attenuation < 10) at: drivers/net/wireless/bcm43xx/bcm43xx_phy.c:1496:bcm43xx_find_lopair()
bcm43xx: ASSERTION FAILED (radio_attenuation < 10) at: drivers/net/wireless/bcm43xx/bcm43xx_phy.c:1496:bcm43xx_find_lopair()
bcm43xx: ASSERTION FAILED (radio_attenuation < 10) at: drivers/net/wireless/bcm43xx/bcm43xx_phy.c:1496:bcm43xx_find_lopair()
bcm43xx: Chip initialized
bcm43xx: 32-bit DMA initialized
bcm43xx: Keys cleared
bcm43xx: Selected 802.11 core (phytype 2)
bcm43xx: ASSERTION FAILED (radio_attenuation < 10) at: drivers/net/wireless/bcm43xx/bcm43xx_phy.c:1496:bcm43xx_find_lopair()
...
Here's iwconfig's output:
eth1 IEEE 802.11b/g ESSID:"WIRELESS" Nickname:"Broadcom 4318"
Mode:Managed Frequency=2.484 GHz Access Point: Invalid
Bit Rate=1 Mb/s Tx-Power=18 dBm
RTS thr:off Fragment thr:off
Encryption key:ABCD-EF12-34 Security mode:open
Link Quality=0/100 Signal level=-256 dBm Noise level=-256 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0
I don't know what else i can do, so suggestions are welcome.
Thanks