Not necessarily, have a good look at how the window sits. Yours could be like Rickya's were the glass is not sitting flush with the rubber or possibly the rubber is worn. A good indication of this is when you wash your car, do you notice any water droplets on the inside??? Regulators were a problem on earlier models which has now been expelled. If your car is still under warranty, then I guess there is no harm in asking especially if it's the fifth time the fault has reoccurred.