bluetooth mouse inspiron 14z disconnects

Windows 8 Pro Danish - Microsoft Sculpt Comfort mouse - on Inspiron 14z 

The mouse works for a while and is then disconnected / turned off. If I turn of the power on the mouse and then on again it works for a while again.

I've seen solutions that I should go to properties in hardware config and disable the “Allow the computer to turn off this device to save power” parameter, but I see no Power Management under advanced tab.

H E L P :)