I'm having the same issue on Ubuntu 10.04 on a Toshiba Portege R705. It happens when I transfer data through the network (eg, backing up my computer), while I'm surfing the net, and while it is idle. It occurs quite frequently actually, a few times a day. It happens during data transfer for sure. Here is what happened (dmesg) while I used rsync: [62557.402259] wlan0: associated [62561.586253] iwlagn 0000:02:00.0: iwl_tx_agg_start on ra = 48:5b:39:42:ba:98 tid = 0 [62958.227431] iwlagn 0000:02:00.0: Microcode SW error detected. Restarting 0x2000000. [62958.319683] Registered led device: iwl-phy0::radio [62958.319708] Registered led device: iwl-phy0::assoc [62958.319731] Registered led device: iwl-phy0::RX [62958.319751] Registered led device: iwl-phy0::TX [62958.326987] iwlagn 0000:02:00.0: Stopping AGG while state not ON or starting [62958.326996] iwlagn 0000:02:00.0: queue number out of range: 0, must be 10 to 19 [62958.327002] ------------[ cut here ]------------ [62958.327035] WARNING: at /build/buildd/linux-2.6.32/net/mac80211/agg-tx.c:150 ___ieee80211_stop_tx_ba_session+0x82/0x90 [mac80211]() [62958.327041] Hardware name: PORTEGE R705 [62958.327044] Modules linked in: isofs binfmt_misc ppdev nls_iso8859_1 nls_cp437 cryptd aes_x86_64 aes_generic vfat fat snd_hda_codec_intelhdmi joydev snd_hda_codec_realtek fbcon tileblit font bitblit softcursor vga16fb vgastate snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_dummy snd_seq_oss arc4 snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq iwlagn i915 snd_timer snd_seq_device iwlcore drm_kms_helper uvcvideo videodev v4l1_compat v4l2_compat_ioctl32 mac80211 snd psmouse serio_raw soundcore toshiba_acpi cfg80211 drm i2c_algo_bit video output snd_page_alloc sdhci_pci sdhci led_class intel_agp lp parport usb_storage ahci e1000e [62958.327127] Pid: 15, comm: events/0 Tainted: G W 2.6.32-24-generic #38-Ubuntu [62958.327131] Call Trace: [62958.327146] [] warn_slowpath_common+0x7b/0xc0 [62958.327153] [] warn_slowpath_null+0x14/0x20 [62958.327170] [] ___ieee80211_stop_tx_ba_session+0x82/0x90 [mac80211] [62958.327188] [] __ieee80211_stop_tx_ba_session+0x7f/0x90 [mac80211] [62958.327206] [] ieee80211_sta_tear_down_BA_sessions+0x27/0x50 [mac80211] [62958.327228] [] ieee80211_reconfig+0x378/0x460 [mac80211] [62958.327244] [] ? ieee80211_restart_work+0x0/0x30 [mac80211] [62958.327259] [] ieee80211_restart_work+0x22/0x30 [mac80211] [62958.327270] [] run_workqueue+0xc7/0x1a0 [62958.327278] [] worker_thread+0xa3/0x110 [62958.327285] [] ? autoremove_wake_function+0x0/0x40 [62958.327292] [] ? worker_thread+0x0/0x110 [62958.327298] [] kthread+0x96/0xa 8-Ubuntu [62958.327131] Call Trace: [62958.327146] [] warn_slowpath_common+0x7b/0xc0 [62958.327153] [] warn_slowpath_null+0x14/0x20 [62958.327170] [] ___ieee80211_stop_tx_ba_session+0x82/0x90 [mac80211] [62958.327188] [] __ieee80211_stop_tx_ba_session+0x7f/0x90 [mac80211] [62958.327206] [] ieee80211_sta_tear_down_BA_sessions+0x27/0x50 [mac80211] [62958.327228] [] ieee80211_reconfig+0x378/0x460 [mac80211] [62958.327244] [] ? ieee80211_restart_work+0x0/0x30 [mac80211] [62958.327259] [] ieee80211_restart_work+0x22/0x30 [mac80211] [62958.327270] [] run_workqueue+0xc7/0x1a0 [62958.327278] [] worker_thread+0xa3/0x110 [62958.327285] [] ? autoremove_wake_function+0x0/0x40 [62958.327292] [] ? worker_thread+0x0/0x110 [62958.327298] [] kthread+0x96/0xa0 [62958.327306] [] child_rip+0xa/0x20 [62958.327313] [] ? kthread+0x0/0xa0 [62958.327318] [] ? child_rip+0x0/0x20 [62958.327323] ---[ end trace 167d17e401847bfe ]--- [63103.788065] wlan0: deauthenticating from 48:5b:39:42:ba:98 by local choice (reason=3) [63104.008801] wlan0: deauthenticating from 48:5b:39:42:ba:98 by local choice (reason=3) [63104.047624] wlan0: direct probe to AP 48:5b:39:42:ba:98 (try 1) [63104.257315] wlan0: direct probe to AP 48:5b:39:42:ba:98 (try 2) [63104.260649] wlan0: direct probe responded [63104.260658] wlan0: authenticate with AP 48:5b:39:42:ba:98 (try 1) [63104.262450] wlan0: authenticated [63104.262483] wlan0: associate with AP 48:5b:39:42:ba:98 (try 1) [63104.265675] wlan0: RX AssocResp from 48:5b:39:42:ba:98 (capab=0x411 status=0 aid=4) [63104.265685] wlan0: associated [63108.867876] iwlagn 0000:02:00.0: iwl_tx_agg_start on ra = 48:5b:39:42:ba:98 tid = 0 [63123.924466] hda-intel: azx_get_response timeout, switching to polling mode: last cmd=0x302f2d00 and this is what happened just now before I posted, while idle for a few minutes: [63123.924466] hda-intel: azx_get_response timeout, switching to polling mode: l ast cmd=0x302f2d00 [63391.394271] iwlagn 0000:02:00.0: Microcode SW error detected. Restarting 0x2 000000. [63391.487940] Registered led device: iwl-phy0::radio [63391.487975] Registered led device: iwl-phy0::assoc [63391.488009] Registered led device: iwl-phy0::RX [63391.488036] Registered led device: iwl-phy0::TX [63391.504317] iwlagn 0000:02:00.0: Stopping AGG while state not ON or starting [63391.504330] iwlagn 0000:02:00.0: queue number out of range: 0, must be 10 to 19 [63391.504338] ------------[ cut here ]------------ [63391.504374] WARNING: at /build/buildd/linux-2.6.32/net/mac80211/agg-tx.c:150 ___ieee80211_stop_tx_ba_session+0x82/0x90 [mac80211]() [63391.504380] Hardware name: PORTEGE R705 [63391.504383] Modules linked in: isofs binfmt_misc ppdev nls_iso8859_1 nls_cp43 7 cryptd aes_x86_64 aes_generic vfat fat snd_hda_codec_intelhdmi joydev snd_hda_codec_realtek fbcon tileblit font bitblit softcursor vga16fb vgastate snd_hda_intel snd_hda_codec snd_hwdep snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_dummy snd_seq_oss arc4 snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq iwlagn i915 snd_timer snd_seq_device iwlcore drm_kms_helper uvcvideo videodev v4l1_compat v4l2_compat_ioctl32 mac80211 snd psmouse serio_raw soundcore toshiba_acpi cfg80211 drm i2c_algo_bit video output snd_page_alloc sdhci_pci sdhci led_class intel_agp lp parport usb_storage ahci e1000e [63391.504465] Pid: 18, comm: events/3 Tainted: G W 2.6.32-24-generic #38-Ubuntu [63391.504470] Call Trace: [63391.504485] [] warn_slowpath_common+0x7b/0xc0 [63391.504492] [] warn_slowpath_null+0x14/0x20 [63391.504510] [] ___ieee80211_stop_tx_ba_session+0x82/0x90 [mac80211] [63391.504528] [] __ieee80211_stop_tx_ba_session+0x7f/0x90 [mac80211] [63391.504546] [] ieee80211_sta_tear_down_BA_sessions+0x27/0x50 [mac80211] [63391.504568] [] ieee80211_reconfig+0x378/0x460 [mac80211] [63391.504585] [] ? ieee80211_restart_work+0x0/0x30 [mac80211] [63391.504603] [] ieee80211_restart_work+0x22/0x30 [mac80211] [63391.504614] [] run_workqueue+0xc7/0x1a0 [63391.504624] [] worker_thread+0xa3/0x110 [63391.504634] [] ? autoremove_wake_function+0x0/0x40 [63391.504644] [] ? worker_thread+0x0/0x110 [63391.504653] [] kthread+0x96/0xa0 [63391.504664] [] child_rip+0xa/0x20 [63391.504673] [] ? kthread+0x0/0xa0 [63391.504691] [] ? child_rip+0x0/0x20 [63391.504697] ---[ end trace 167d17e401847bff ]--- [63485.260404] wlan0: deauthenticating from 48:5b:39:42:ba:98 by local choice (reason=3) [63485.371063] wlan0: deauthenticating from 48:5b:39:42:ba:98 by local choice (reason=3) [63485.419730] wlan0: direct probe to AP 48:5b:39:42:ba:98 (try 1) [63485.423572] wlan0: direct probe responded [63485.423577] wlan0: authenticate with AP 48:5b:39:42:ba:98 (try 1) [63485.425333] wlan0: authenticated [63485.425355] wlan0: associate with AP 48:5b:39:42:ba:98 (try 1) [63485.428495] wlan0: RX AssocResp from 48:5b:39:42:ba:98 (capab=0x411 status=0 aid=4) [63485.428498] wlan0: associated [63489.376115] iwlagn 0000:02:00.0: iwl_tx_agg_start on ra = 48:5b:39:42:ba:98 tid = 0 I must say this didn't happen in early July when I installed ubuntu, so I'm guessing it's a kernel issue?