This is a bug that reminded me that this is OSS and not tested commercial software … Sometimes, when I wake my laptop up from sleep, the Power Save module warns me that the battery level is critical (which was NEVER true so far) and that the laptop will be suspended now. The battery icon, at this time, still shows the correct loading status (so far it was always around 90 percent or more). If I'm happy and the laptop is connected to AC, I get a second message that AC has been plugged in and suspending is aborted. If not, the laptop is suspended, and since, for some reason, the suspended state is not loaded when re-booting, all work that was not saved till then is lost. PLEASE add more tests, e.g. after a few seconds, to check if the battery is REALLY low or maybe not so really. I'm not sure, but it might be related that I put the laptop into sleep mode and then unplugged the power. When waking up, the power icon still shows that the laptop is plugged, although it is not. It is definitely not the case since the warning did not come right after waking up, but only after putting it in sleep mode and waking it up twice again. Reproducible: Sometimes
Which KDE version are you using?
Your KDE version 4.8 is too old and no longer maintained. Please update to latest stable (KDE 4.10.5) or previous stable version (KDE 4.9.5).
Can't you please at least ask the author if he fixed this bug. Otherwise I (or sb else) will just report it for 4.9 again, and you again tell me to upgrade, and so on, and it never gets fixed. I see this happen too often. Thanks.
If it still happens on a recent KDE, simply reopen the bug.