How are you launching it? The wing (lift) should support the glider right as you start your spin and your fingers are basically just holding the launch peg just enough to keep it from flying out of your hand until the release. It may happen depending on how you hold it just prior to launch too...if youre supporting the weight of the glider by the tip just before you start the spin, it can stress it and crease/crack it.
I'd get either some foam safe CA or epoxy and fill the crack under the skin. If its warped or creased, a bit of warm water can usually straighten it out (though I havent tried that myself).
Theres a few nice slow-mo videos on youtube of people showing their launch techniques you could check out too. I miss my DLG...
Nick