When we first received our machine and homed it for the first time we had an overload warning as the Y & Y2 motors were not perfectly aligned and the gantry wasn't square. We also had a lost pulse on the Z when we first received the machine but haven't seen it again since. Noise is a major issue with some things like this, maybe worth investigating that further if you keep getting random alarms but overloads are pretty specific and may be something relating to these kinds of actual problems.