My cameras have all been field cameras and as a result are always stored with the bellows completly compressed. Glue wears out with oxidation, heat, humidity and age. Keep the bellows clean by vacuuming them out from time to time and treat them as you would any vinyl or leather product with an occassional coating of some lubricant designed for them - on the outside. I use one of the products designed for automobile vinyl on my bellows - I forget which one now, but it's the one with the little Viking on it. Use it moderatley and check before use to make sure it won't interact negatively with the adhesive used in your bellows or the bellows material itself. You might try contacting Toyo and see what if any info/advice they may have on the subject.