MacBook :: Cracking - Plastic Border Above The Screen

i have, in the past, had my macbook's palm rest crack. I brought it into apple, and was happy to have it replaced, free of charge. Recently, the plastic cracked again, this time in a new place. The plastic border above the screen; more particularly the area directly above the indents that come out to help separate the screen from the keyboard. I'm not sure if this is covered by Apple's policy with cracked palmrests. Any advice or help is appreciated of course. If you think Apple won't help me, would it be risky to use an adhesive to hold the plastic down, as it's near the screen?