FWIW, hawk,sounds exactly like my problem. Over the space of ten years had three flat-on-my-back-for-two-days incidents and said "enough of this!"
I do 15-20 mins a day of simple exercises stressing flexibility and abs primarily, and I've not had a spasm session in at least four years. It's worth it, believe me! Plus you get bragging rights among your buddies about still being able to touch your toes