Bottom case too flexible?

[lbwarped]

When I press on the bottom center of my SB (i7, 256, dGPU) and let go, I hear a sound like adhesive separating from another surface. I wonder if this is some kind of thermal paste? I worry about the longevity if the bottom of the case is flexible like this.

Anyone else hear this or have ideas?

 

[jasbur]

I just noticed this today. I assume it's the adhesive holding the bottom cover on.
It's starting to annoy me.