Version:            (using Devel)
OS:                Linux
Installed from:    Compiled sources

When I want to move my laptop, I disconnect the AC adaptor, I hear the notification and the computer starts working on battery. OK. Then, after a few seconds, I plug into another socket, so the scheme is switched to "performance". OK. 

But when, AFTER MANY MINUTES (or even hours) - this detail is important - I want to move my laptop back to its original place and I disconnect the AC again, I can hear the notification noise twice, then after a few seconds the same sound for a third time, and the laptop suspends.

What is worse, after pressing the "on" button, sometimes I do not come back to the previous state, but see KDM: the KDE session has been closed! (sometimes; other times it correctly resumes the previous state, but the issue with the inappropriate suspension is always here).

Using Arch Linux, happening at least in KDE versions 4.2.2 and 4.2.3. Please note the "after many minutes" detail: if you plug and unplug several times within seconds (and maybe a few minutes), the problem does not happen.