Thank you, firs i think is my code.

 I use this code on a loop with InTheHand.Net.Personal.dll (v 2.2.0) on windows XP 32bit: BluetoothDeviceInfo btdev = new BluetoothDeviceInfo(btAddress); btdev.Refresh(); Console.WriteLine(btdev.LastUsed.ToLocalTime().ToString()); Console.WriteLine(btdev.LastSeen.ToLocalTime().ToString());  the LastUsed always is equal with ...