It won't really make a diffrence if you leave the tube on or off if you have the cap off in the humidor. Either way the cigar will get the same humidity benefits from the humidor, however if you remove the tube it will give you more space in your humidor. Although if you tend to "play" with your cigars alot you might want to leave the tube on to keep from damaging the wrapper of the cigar. The tubes shouldn't be a problem in the humidor, more than likely the problem has something to do with not seasoning the humidor, the humidifcation element or the humidor/seal itself.