Intel 5300 wlan does not work

Ubuntu 9.10, Linux 2.6.31-14-generic #48-Ubuntu SMP Fri Oct 16 14:05:01 UTC 2009 x86_64 unknown unknown GNU/Linux

Intel 5300 mini pci-e wlan card. Netgear WNDR3700 access point/router.

No connection on 2.4G and 5GHz . Sometimes the wlan connects, but does never last more than a few minutes.
Removing / Reloading all iwlxxxx modules does not help. Same problem with "network-manager " and "wicd".

Output of dmesg :

[ 26.793295] iwlagn: Intel(R) Wireless WiFi Link AGN driver for Linux, 1.3.27k
[ 26.793307] iwlagn: Copyright(c) 2003-2009 Intel Corporation
[ 26.795322] ACPI: PCI Interrupt Link [LN3A] enabled at IRQ 19
[ 26.795335] alloc irq_desc for 19 on node 0
[ 26.795341] alloc kstat_irqs on node 0
[ 26.795358] iwlagn 0000:04:00.0: PCI INT A -> Link[LN3A] -> GSI 19 (level, low) -> IRQ 19
[ 26.795372] iwlagn 0000:04:00.0: setting latency timer to 64
[ 26.795424] iwlagn 0000:04:00.0: Detected Intel Wireless WiFi Link 5300AGN REV=0x24
[ 26.830716] iwlagn 0000:04:00.0: Tunable channels: 13 802.11bg, 24 802.11a channels
[ 26.830776] alloc irq_desc for 30 on node 0
[ 26.830781] alloc kstat_irqs on node 0
[ 26.830827] iwlagn 0000:04:00.0: irq 30 for MSI/MSI-X
[ 26.944389] phy0: Selected rate control algorithm 'iwl-agn-rs'
[ 27.965392] usbcore: registered new interface driver snd-usb-audio
[ 28.418384] Installing knfsd (copyright (C) 1996 <email address hidden>).
[ 28.473078] HDA Intel 0000:00:08.0: power state changed by ACPI to D0
[ 28.474356] ACPI: PCI Interrupt Link [LAZA] enabled at IRQ 23
[ 28.474385] HDA Intel 0000:00:08.0: PCI INT A -> Link[LAZA] -> GSI 23 (level, low) -> IRQ 23
[ 28.474470] HDA Intel 0000:00:08.0: setting latency timer to 64
[ 28.482596] cfg80211: World regulatory domain updated:
[ 28.482616] (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp)
[ 28.482642] (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
[ 28.482665] (2457000 KHz - 2482000 KHz @ 20000 KHz), (300 mBi, 2000 mBm)
[ 28.482688] (2474000 KHz - 2494000 KHz @ 20000 KHz), (300 mBi, 2000 mBm)
[ 28.482711] (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
[ 28.482735] (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 2000 mBm)
[ 28.820396] __ratelimit: 3 callbacks suppressed
<some other messages omitted>
[ 49.376951] iwlagn 0000:04:00.0: firmware: requesting iwlwifi-5000-2.ucode
[ 49.575154] iwlagn 0000:04:00.0: loaded firmware version 8.24.2.12
[ 49.756093] Registered led device: iwl-phy0::radio
[ 49.756141] Registered led device: iwl-phy0::assoc
[ 49.756183] Registered led device: iwl-phy0::RX
[ 49.756224] Registered led device: iwl-phy0::TX
[ 49.782000] ADDRCONF(NETDEV_UP): wlan0: link is not ready
[ 50.642789] cfg80211: Found new beacon on frequency: 5180 MHz (Ch 36) on phy0
[ 50.789044] ppdev: user-space parallel port driver
[ 55.092397] eth0: no link during initialization.
[ 55.094204] ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 60.883197] eth0: no link during initialization.
[ 60.884869] ADDRCONF(NETDEV_UP): eth0: link is not ready
[ 61.314866] Registered led device: iwl-phy0::radio
[ 61.314916] Registered led device: iwl-phy0::assoc
[ 61.314958] Registered led device: iwl-phy0::RX
[ 61.315001] Registered led device: iwl-phy0::TX
[ 61.345624] ADDRCONF(NETDEV_UP): wlan0: link is not ready
[ 64.772465] wlan0: authenticate with AP 00:24:b2:57:0e:ee
[ 64.970031] wlan0: authenticate with AP 00:24:b2:57:0e:ee
[ 64.972833] wlan0: authenticated
[ 64.972839] wlan0: associate with AP 00:24:b2:57:0e:ee
[ 64.973716] wlan0: RX AssocResp from 00:24:b2:57:0e:ee (capab=0x411 status=0 aid=1)
[ 64.973723] wlan0: associated
[ 64.976656] ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[ 65.200374] Intel AES-NI instructions are not detected.
[ 65.235073] padlock: VIA PadLock not detected.
[ 75.300015] wlan0: no IPv6 routers present
[ 241.516554] iwlagn 0000:04:00.0: iwl_tx_agg_start on ra = 00:24:b2:57:0e:ee tid = 0
[ 277.426072] iwlagn 0000:04:00.0: ERROR: No TX rate available.
[ 277.431624] iwlagn 0000:04:00.0: ERROR: No TX rate available.
[ 277.432368] iwlagn 0000:04:00.0: ERROR: No TX rate available.
[ 277.442636] iwlagn 0000:04:00.0: ERROR: No TX rate available.
[ 277.444616] iwlagn 0000:04:00.0: ERROR: No TX rate available.
[ 277.445100] iwlagn 0000:04:00.0: ERROR: No TX rate available.
<The "No TX rate available" messages continue>

Rarely the card reconnects for a short time. In this case dmesg output is :

[ 566.350064] iwlagn 0000:04:00.0: ERROR: No TX rate available.
[ 566.660096] iwlagn 0000:04:00.0: ERROR: No TX rate available.
[ 566.660135] iwlagn 0000:04:00.0: ERROR: No TX rate available.
[ 566.850097] iwlagn 0000:04:00.0: ERROR: No TX rate available.
[ 567.280083] iwlagn 0000:04:00.0: ERROR: No TX rate available.
[ 567.570782] wlan0: deauthenticated (Reason: 2)
[ 568.570032] wlan0: direct probe to AP 00:24:b2:57:0e:ee try 1
[ 568.570964] wlan0 direct probe responded
[ 568.570971] wlan0: authenticate with AP 00:24:b2:57:0e:ee
[ 568.571370] wlan0: authenticated
[ 568.571376] wlan0: associate with AP 00:24:b2:57:0e:ee
[ 568.572272] wlan0: RX ReassocResp from 00:24:b2:57:0e:ee (capab=0x411 status=0 aid=1)
[ 568.572279] wlan0: associated