How to disable wifi power management (rtlwifi, rtl8192cu)

There are several access points nearby with greater signal strength than Becks, to whom you are connected. I suspect Network manager is seeing these access points with better strength and attempting to roam to another. I suggest you right-click the Network Manager icon and select Edit Connections. Edit the wireless connection Becks as here:

Mark it to connect automatically and fill in Becks BSSID (MAC address) to tell Network Manager that you wish to connect to only Becks and only the MAC address you specified.