Macbook Pro is making clicking noise...HELP!

If someone can please help me with my Macbook Pro problem...I purchased a Macbook Pro 15" (the good one) in Sept. 2011. The 2nd day I had it, I noticed this very faint pop noise when I would open my Macbook either in the morning after sitting all night, or if would be closed for about an hour it would make this pop/click noise coming from the piece that connects the screen to the laptop itself. I did research on it, and found that other customers were having this problem with the 13"...last month I decided to bring it in to the Apple Store and I explained them the problem. They opened it, said there was no problem, and thought it was "going from cold to hot by the friction produced when opening", my friends all have macs and say they never had this problem. I am honestly very worried now, because this does it countless times a day. I'd be really ****** if a year from now after my warranty is up it falls apart. Any input would be much appreciated! Thanks for reading! *Added note, this is very hard to show the Apple specialist because it only does it once when opened, and usually the apple store is VERY loud so they think I'm crazy. (I'll go as far as recording every time I open my mac) Sometimes the noise is louder than others.