this bug also affects me in fresh installed maverick.
network speed over wifi is never faster than 150kb/s. Even when i copy stuff from my local network storage over nfs.

regards oliver

dmesg:
[ 2181.202588] iwl3945 0000:0c:00.0: Detected Intel Wireless WiFi Link 3945ABG
[ 2181.202736] iwl3945 0000:0c:00.0: irq 43 for MSI/MSI-X
[ 2181.203341] phy0: Selected rate control algorithm 'iwl-3945-rs'
[ 2184.755327] ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 2184.785415] iwl3945 0000:0c:00.0: loaded firmware version 15.32.2.9
[ 2184.862250] ADDRCONF(NETDEV_UP): wlan0: link is not ready
[ 2190.598031] wlan0: authenticate with 00:1f:3f:a4:80:c1 (try 1)
[ 2190.603331] wlan0: authenticated
[ 2190.604681] wlan0: associate with 00:1f:3f:a4:80:c1 (try 1)
[ 2190.624421] wlan0: RX AssocResp from 00:1f:3f:a4:80:c1 (capab=0x431 status=0 aid=5)
[ 2190.624429] wlan0: associated
[ 2190.633272] ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[ 2201.440085] wlan0: no IPv6 routers present
[ 2700.721281] b44 ssb0:0: eth0: powering down PHY
[ 2700.956153] wlan0: deauthenticating from 00:1f:3f:a4:80:c1 by local choice (reason=3)
[ 2701.019663] cfg80211: All devices are disconnected, going to restore regulatory settings
[ 2701.019674] cfg80211: Restoring regulatory settings
[ 2701.019681] cfg80211: Calling CRDA to update world regulatory domain
[ 2701.029362] cfg80211: World regulatory domain updated:
[ 2701.029369]     (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)
[ 2701.029377]     (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
[ 2701.029383]     (2457000 KHz - 2482000 KHz @ 20000 KHz), (300 mBi, 2000 mBm)
[ 2701.029390]     (2474000 KHz - 2494000 KHz @ 20000 KHz), (300 mBi, 2000 mBm)
[ 2701.029396]     (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
[ 2701.029403]     (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
[ 2722.649596] iwl3945 0000:0c:00.0: PCI INT A disabled
[ 2768.237253] ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 2801.445177] cfg80211: Calling CRDA to update world regulatory domain
[ 2801.452802] cfg80211: World regulatory domain updated:
[ 2801.452806]     (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)
[ 2801.452811]     (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
[ 2801.452815]     (2457000 KHz - 2482000 KHz @ 20000 KHz), (300 mBi, 2000 mBm)
[ 2801.452819]     (2474000 KHz - 2494000 KHz @ 20000 KHz), (300 mBi, 2000 mBm)
[ 2801.452823]     (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
[ 2801.452826]     (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
[ 2801.519779] iwl3945: Intel(R) PRO/Wireless 3945ABG/BG Network Connection driver for Linux, in-tree:s
[ 2801.519785] iwl3945: Copyright(c) 2003-2010 Intel Corporation
[ 2801.519870] iwl3945 0000:0c:00.0: PCI INT A -> GSI 17 (level, low) -> IRQ 17
[ 2801.519892] iwl3945 0000:0c:00.0: setting latency timer to 64
[ 2801.560347] iwl3945 0000:0c:00.0: Tunable channels: 13 802.11bg, 23 802.11a channels
[ 2801.560353] iwl3945 0000:0c:00.0: Detected Intel Wireless WiFi Link 3945ABG
[ 2801.560501] iwl3945 0000:0c:00.0: irq 43 for MSI/MSI-X
[ 2801.561138] phy0: Selected rate control algorithm 'iwl-3945-rs'
[ 2801.584927] iwl3945 0000:0c:00.0: loaded firmware version 15.32.2.9
[ 2801.666377] ADDRCONF(NETDEV_UP): wlan0: link is not ready
[ 2814.505726] wlan0: authenticate with 00:1f:3f:a4:80:c1 (try 1)
[ 2814.508993] wlan0: authenticated
[ 2814.510076] wlan0: associate with 00:1f:3f:a4:80:c1 (try 1)
[ 2814.708100] wlan0: associate with 00:1f:3f:a4:80:c1 (try 2)
[ 2814.733784] wlan0: RX AssocResp from 00:1f:3f:a4:80:c1 (capab=0x431 status=0 aid=5)
[ 2814.733792] wlan0: associated
[ 2814.742343] ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[ 2825.424059] wlan0: no IPv6 routers present