Thanks all. I can't believe I didn't notice this, and those of you who got a laugh are sure to continue laughing.......

I just found a rotting banana in the bottom of the big pocket of my backpack where I keep the tablet. It must have been there for days, maybe a week. What a ****ing tool I am!

While I'm no expert in these things, my guess is that the banana let off some gas or other that may--right?--have latched onto card/inside of the slot? But then, is it weird that the ONLY place exhibiting the symptom is on the INSIDE of the tablet?