I have four fittings using triphospher tubes as under kitchen cabinet illumination. Anyone know the life expectancy of the tubes and the fittings. Ive had to replace two of these fittings already. There only about 18 months old and are used sparingly. Today one i only bought 6 months ago has stopped working, up to a couple of days ago it would not light but if i touched it would come on. If i could find the reciept for the poxy thing it would go right back. The fittings all use different length tubes so i cant try another one to see if its tube or fitting thats packed up. The last time i priced these tubes they wernt exactly cheap, so i dont want to buy one if its the unit thats bit the dust.