Mine does that too. If I go to edit a character wearing a preset, it goes down a number and puts on another, but I just go and put its original preset back on and it's fine. If that is what you're talking about, it's just a glitch and nothing more. ^^
Ahh this has happened to me a couple times. I've always seen it as a mere glitch. I have various presets for my characters, and sometimes when I go to edit a character that has a preset on, randomly one of my other presets will show up on it. I simply just remove it, and put the designated preset back on. =)