Some updates today: I put the hardrive with Maverick into my laptop and installed new updates. Then I removed the power lead and the system crashed. Again. So no progress in solving this bug yet. I started to dig in my system little bit: 1.) I removed the internal WiFi card (based on Intel 4965AGN), then I booted the Maverick, removed the power lead and NOTHING! No crash! But without wifi my laptop is quite useless, so: 2.) I plugged the USB WiFi stick (based on RaLink chipset RT2500USB), removed the power lead and NOTHING! No crash! I have spare internal WiFi card, so I removed the USB WiFi stick and: 3.) I plugged another internal WiFi card (based on Broadcom BCM4315 chipset), booted Maverick, installed restricted kernel drivers, restarted the system and removed the power lead - NOTHING! No crash! Now I started to suspect the Intel 4965AGN WiFi card to be the cause of all the problems. So I removed the Broadcom card and plugged the Intel back. Restarted, removed the power lead and CRASH! So we are closer now, at least in my case. I started to study the logs, I did this before but because of crashes there was nothing. But today I found two pieces of information: The last rows in the kern.log are suspicious: kernel: [ 119.059334] atkbd serio0: Unknown key pressed (translated set 2, code 0xee on isa0060/serio0). kernel: [ 119.059344] atkbd serio0: Use 'setkeycodes e06e ' to make it known. kernel: [ 119.069352] atkbd serio0: Unknown key released (translated set 2, code 0xee on isa0060/serio0). kernel: [ 119.069360] atkbd serio0: Use 'setkeycodes e06e ' to make it known. ...(my comment - these 4 messages are harmless, they always appear when I remove the power lead)... kernel: [ 121.272191] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro,commit=600 ...(my comment - following messages are the latest before crash)... kernel: [ 126.610093] No probe response from AP 00:16:01:af:aa:7c after 500ms, disconnecting. kernel: [ 127.110065] iwlagn 0000:05:00.0: Error sending REPLY_RXON: time out after 500ms. kernel: [ 127.110079] iwlagn 0000:05:00.0: Error setting new RXON (-110) kernel: [ 127.610087] iwlagn 0000:05:00.0: Error sending REPLY_REMOVE_STA: time out after 500ms. kernel: [ 127.610103] iwlagn 0000:05:00.0: Error removing station 00:16:01:af:aa:7c kernel: [ 127.662743] cfg80211: All devices are disconnected, going to restore regulatory settings kernel: [ 127.662763] cfg80211: Restoring regulatory settings kernel: [ 127.662773] cfg80211: Calling CRDA to update world regulatory domain kernel: [ 127.675943] cfg80211: World regulatory domain updated: kernel: [ 127.675953] (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp) kernel: [ 127.675961] (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2000 mBm) kernel: [ 127.675968] (2457000 KHz - 2482000 KHz @ 20000 KHz), (300 mBi, 2000 mBm) kernel: [ 127.675975] (2474000 KHz - 2494000 KHz @ 20000 KHz), (300 mBi, 2000 mBm) kernel: [ 127.675983] (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 2000 mBm) kernel: [ 127.675989] (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 2000 mBm) kernel: [ 127.873202] iwlagn 0000:05:00.0: HARDWARE GONE?? INTA == 0xffffffff kernel: [ 127.873202] iwlagn 0000:05:00.0: HARDWARE GONE?? INTA == 0xffffffff kernel: [ 128.466123] iwlagn 0000:05:00.0: Error sending REPLY_SCAN_CMD: time out after 500ms. kernel: [ 128.960078] iwlagn 0000:05:00.0: Error sending REPLY_TX_PWR_TABLE_CMD: time out after 500ms. I also found something interesting in the pm-powersave.log: Running hook /usr/lib/pm-utils/power.d/wireless false: Turning powersave for wlan0 off...Error for wireless request "Set Power Management" (8B2C) : SET failed on device wlan0 ; Operation not supported. Failed. /usr/lib/pm-utils/power.d/wireless false: success. So what's that mean??? What I think happened - gnome power management system detectes that power lead has been removed and tries to force the intel wifi card into some power saving mode. Intel wifi driver probably doesn't recognise the command OR screwes something. Maybe it even crashes the wifi card and the card consequently crashes the PCI-express bus between card slot and northbridge. Why this crashes the whole system I don't know. My suggestion for gnome power management subsystem developers is - please find the way how to blacklist the Intel wifi driver from being pushed into power save mode or better inform the Intel driver developers about the problem. Now I'm going to put back the hardrive with fully operating 10.04. I will wait for some usefull replies. Bye for now.