I'm having a problem with solid/upower/udisks in KDE 4.7. The power management controls in systemsettings are disabled and I get the following error:

virtual QStringList Solid::Backends::UPower::UPowerManager::allDevices() error: "org.freedesktop.DBus.Error.Disconnected"

When I run "solid-hardware list", I get no entries for power management functions and the following two errors:

QStringList Solid::Backends::UDisks::UDisksManager::allDevicesInternal() error: "org.freedesktop.DBus.Error.Disconnected"
virtual QStringList Solid::Backends::UPower::UPowerManager::allDevices() error: "org.freedesktop.DBus.Error.Disconnected"

It seems the solid backends for both upower and udisks are broken.

My specs:
LFS linux
KDE 4.7
QT 4.7.4
udisks-1.0.4
upower-0.9.13
dbus-1.4.14
polkit-0.102
consolekit-0.4.5

I'm running on a laptop so I really need power management.

Any help appreciated.

I would suggest checking your system logs, it seems that UPower/UDisks are crashing.