you must be really lucky to get 2 defective systems in a row.

My 3DS actually started making the noise I believe you are describing in the op when pressing down on the a button. I started noticing it when I was playing either Super Mario Land 1 + 2 from the VC. When holding down the run button and then hitting the jump button was when I first started hearing it. It almost sounds like it needs some lube or WD40 on the buttons. I won't do anything yet to it and it seems like it is only the Mario VC games that I notice it so far (I haven't played that much Super Mario 3D Land) again since getting MK7. Anyways, this noise is kind of pissing me off too but I am not sure what to do about it yet (since it is not happening that often I kind of put it on the back burner for now).

Anyways, I would probably just go through Nintendo unless the store is willing to replace it again.  Reminds me when I first bought the DS phat.  I took it out and noticed the bottom touch screen was dented on one side.  I then tried to see if it still worked and of course the touch screen was screwed up.  I took it back to Gamestop while on the phone with a Nintendo rep (lived across the street from Gamestop) so the Nintendo rep could talk to the employee.  I suppose they believed me and the story (I sent the receipt back to them to show that on the same day purchased was when I called to report).  I sent in the DS free shipping and they sent me another one free of charge.  The employee at the Gamestop was like good thing you didn't purchase our protection plan because you would have used it up on the first day.  So basically I could have purchased a protection plan (probably 15 or so dollars) and had to use it right away due to getting a damaged system out of the box.  I would then have to repurchase another plan for the new.  That is when it is better off to call Nintendo.

Loose screens? NO PROBLEM. Get a crystal case and fit your 3DS into it and it'll stay as solid as hell.

Well it worked for me. It's freaking tight now (mainly due to the tight joints of the case itself).

It also doesn't help that electronics are getting more fragile as they get more complicated and the shipping companies are throwing the packages around like garbage.

I bought a freezer last month or so and they managed to put a dent to it when that thing is sturdy with steel frames or something.

which case do you have? i am highly interrested.

the Zelda Armor whateverthingy looks cool, but i dunno... o:

edit @seth:

... <.< have the 'squeaking button problem' on the A button on the new one, too. had it also on my first Dual Shock 2, appeared 6 Years after buying the PS2 (LOL) and only because my nephew had eaten with his hands and started playing games on my console without me noticing. i fixed both the 3DS (for now) and the Controller temporarily by doing a drop of water on my finger. it will run down the button, but not into the hardware, it will only smoothen the button, erasing the noise. (as i said, temporarily. and i dont recommend it, since i learned how to do it back then, i dont want people to ruin their handhelds lol ^^)

I have three DS Phats. All three have broken hinges. If you want, I'll Swapnote you a pic (You ARE on my 3DS friends list, aren't you? If not, "what's wrong with you"?).

Anyway, the 3DS does have a very slight wobble between the two screens. Don't know why that is, though. You may as well keep the one you have. If it's too much, you can always go with the PSV or you can rub molasses on the hinge. That'll tighten it up!