Shift Lock Release

I've been driving a 2008 Hyundai Sonata lately and it is a pretty nice car. We picked it up a couple of years ago so dutiful daughter would have something to drive to work. We looked around for a bit, but anything that looked like a possible deal got snapped up before we could make a decision and we were running out of time. My mechanic had this one for sale and while it was a bit more than we were originally shooting for, it wasn't out of reach, so we bought it. Dutiful daughter drove it for ten months and then ran away to South America. Kids these days, I tell you, no respect.
    So I take to driving it occasionally, you know, just to make sure it's still running smoothly, and I notice that it's a little larger than Chrysler Sebring, the infamous. For one thing, I can sit up straight whereas in the Chrysler I end up leaning on the console. For another my friend Jack can get in without having to struggle. I gave him a ride in the Chrysler, once. That was enough.
 Anyway, everything is going smoothly until I get back from the train station this morning and it won't shift into park. It will shift into neutral, drive and low, but not into reverse or park. What's going on here? Then I notice that the ESC (Electronic Stability Control) light is on, and pushing the ESC button doesn't change anything. Hmmmph. Then I notice this little label near the shift gate on the console, Shift Lock Release, next to a little tab and hole. What's the owner's manual got to say about this? There is a folder in the glove box full of papers, but they are all warranty dispute resolution procedures. Nothing about how the car actually works. Fine, turn the engine off, leave the key in the ignition (it won't come out unless the shift lever is in park. Notice anything funny about the picture?), go inside and look it up on the internet. Root around for a tiny screwdriver, return to the car, pry out the little tab, push down with the screwdriver, and presto! We have park and I have my key.
    Rumor has it that the problem is with the brake light circuit.