Problems involved in the bubble dynamics models which have been suggested to explain the sonoluminesence phenomena from a single bubble under ultrasound were discussed. One of the problems is proper choice of the time scale of the driving force, which is related to numerical artifacts due to the mismatch between the natural frequency of an oscillator (bubble) and the characteristic frequency of the applied force. Such problem may occur in a nonlinear oscillator whose behavior is crucially dependent on the frequency of the applied force. The characteristics of bubble behavior for the sonoluminescing gas bubble and the artificial resonance problem encountered during the numerical evaluation of such nonlinear system were also discussed.