Bushings never really fail. Where are you? I was in Sacramento and had my board in the trunk of the car. The bushings were like bubble gum when I went to use it.
Like @johnpowell says check to see if they are gummy and also look for cracks. I had a set that actually warped out of shape. (I kept it in my back window of my car- not good thinking)
Are your bearings shoved all the way in the wheels? How loose are your axle nuts? If your wheels are flatspotted or coned from not rotating them that will make it ride like shit.