I just stumbled upon a thread where someone had a problem with his headset not being detected anymore. Someone suggested that the problem could be caused by "pc connectivity manager", which comments out the line "DisablePlugins = network,input,hal" in the file /etc/bluetooth/main.conf.

Since I also have pc connectivity manager installed, I will try if uncommenting this line is a solution for me later today. Will let you guys know how it works out.