In several superconducting applications, low energy losses are strictly demanding. In superconducting films, the dissipative flux flow state plays a role in the stability of the superconducting state in those devices that can operate just above the critical current (Ic). Therefore, details of the current-voltage (I- V) characteristics and in particular of current instabilities from the flux flow state to the normal one can become significant. We study current stability in the flux flow dissipative state by a proper current-voltage measurement mode. Low-temperature superconducting films have been investigated to demonstrate that the current stability range above Ic can be increased by light ion irradiation.