When i remove the AC power cable from my laptop, the computer goes to sleep.

Bug seems to be fixed, after "apt-get upgrade" today (14-09-09), computer doesn't sleep anymore after removing AC power cable. Maybe some guy who is responsible can mark this bug as solved?

On my sony vaio vpcw11s1e, I can confirm this bug. unplugging the power cord in gnome makes the system go to standby. I just bought the computer and put Ubuntu 9.10 on it (fresh standard install of the final version):
kirstin@vaio:~$ cat /proc/version
Linux version 2.6.31-14-generic (buildd@rothera) (gcc version 4.4.1 (Ubuntu 4.4.1-4ubuntu8) ) #48-Ubuntu SMP Fri Oct 16 14:04:26 UTC 2009

the acpi event it receives on unplugging is:
processor CPU0 00000081 00000000
processor CPU1 00000081 00000000
battery BAT1 00000080 00000001

This is probably connected to an issue with the gnome-power-manager or pm-utils, since it doesn't happen in gnome-safe mode or when I use another WM such as fluxbox.

as a workaround for this problem on my sony netbook, I used the gconf-editor to change the behaviour of the gnome-power-manager. I set the key /apps/gnome-power-manager/actions/critical_battery from "suspend" to "nothing". I will have to pay attention to the battery myself now, but at least I can continue working after plugging and unplugging of the ac-cord until this bug is fixed.

This bug isn't fixed! My updated Karmic still has this issue...please don't duplicate bug with status "new" into bug that "seems" fixed...

I think a have a related problem;
When starting my vaio k415b on battery power the boot hangs on the splash screen (no futher activity)
On AC power everything works perfect.
Found als a similar post on http://ubuntuforums.org/showthread.php?t=1308026
This looks like a broader bug and not gnome related........... (did not file a seperate one (yet))

as posted on Ubutuforums
http://ubuntuforums.org/showthread.php?p=8549145

I can confirm this bug on my installation of 9.10 as well. ... a Dell 700m. Same exact symptoms:
Running on AC>unplug cable>goes to standby
Running on Battery>plug in ac cable>goes into standby.
I thought it was my battery, as this lt is old, and the battery is end of life. It keeps a charge for a bout 7 minutes. I have a new extended life batt coming hopefully tomorrow.

This is more of an annoyance than anything. I am a complet newb, and am fairly smitten with ubuntu already

I try to use gconf-editor to fix this problem...
nothing happened....

I second what Ludditic says.

I used the temp fix that Zapter posted and am working for the time being.

Andy

Please kill gnome-power-manager (killall gnome-power-manager) and then run "gnome-power-manager --verbose" in a terminal. Then perform the steps required to reproduce your bug. Then take the output and upload it here.

This sounds rather similar to Bug #425411, though. It would be nice if you could confirm whether it is the same bug (fix is in karmic-proposed, see https://wiki.ubuntu.com/Testing/EnableProposed for how to test).

In which version of gnome-power-manager was fixed bug Bug #425411? I've my system up to date (and proposed enabled), but I can't see any difference on this bug...I've tried to capture a log of gnome-power-manager, but when I restart it on verbose mode the problem disappears...

I also still have this problem using a regularly updated 9.10 on a Samsung X20...

When I remove the power-cord, system goes to sleep, after next reboot it goes to sleep again, after the second reboot I can work again... this takes at least 5mins and is the most annoying bug I've experienced since the first ubuntu!

I can confirm this issue also. I have 2 Acer Aspire Ones with Lucid, and both have a (physical) problem with the power cord, so that charging turns off if I slightly move the cable. The problem is that every time that happens they go to sleep. Unlike some cases I've read, my netbooks can continue working after waking up.

The issue that the netbook is going to sleep can be solved in gnome-powermanger

I set the action for "When lid gets closed" (my ubuntu is Dutch, sorry for translation) to blank screen or nothing.

Then when unplugging the power cable the netbook should blank the screen or just do nothing.

It works for me.

Mr T, I feel with you. Got exacly the same issue on hp 2133 ("mini-note"). That's a REALLY ugly bug. Hope we'll be able to fix it soon.

I made an interresting observation as to what could be the reason why the laptop goes to standby every time: When I turn it on again after the unwanted suspend, I see a message "battery: 94% - 4 minutes left" - which is of course wrong. It should read "3hrs left". But somehow upower, gnome-power-manager and gnome-power-statistics get confused and give wrong info. Funny enough, windows (vista) seems to be confused as well somehow. If i boot vista, it shows me an almost empty battery bar, while the tooltip says "95% charged". ... Most confusing!

Attached find the output of "gnome-power-manager --verbose" of one cycle: plug out power chord with battery fully charged, wait for suspend, plug in, resume.

Note that even though the log talks about hibernating, the laptop never hibernated ... just suspended (twice! ... once right, then once again "half-heartedly" - without locking the gnome-session ... don't ask why ... its UGLY)

I have a similar problem when I remove power on the DC side of the charger. Ubuntu detects a low battery then shutsdown. Cancel is to no avail. If I remove the power on the AC side (wall plug) its fine. My laptop is a Toshiba Satellite A200. I think the detect for low battery is a little too sensitive - need to increase a timer somewhere as Ubuntu sees a power blip when the DC is removed.