First off, sorry you made a forum topic just to have everyone answer you with crap that's completely unrelated to your problem. That's the internet for ya.
Yes, I have also experienced the problem you've described with the LED notification light blinking when there is no message or notification. I've been getting so much bad news lately that the stupid light has become a source of anxiety for me rather than a helpful feature. As a result, I've had to disable it completely. I have noticed, though, that it tends to get triggered with the hand wave gesture you use to light up your screen and check your missed calls/texts/battery power. I'll have no notifications, wave my hand over the phone, and the light starts blinking long after the screen has turned back off. I also turned this feature off, since I don't see the point in waving my hand over my phone like an idiot 3 or 4 times to possibly see something I can pull up in 1 second every time by just pressing a button.
I've submitted a ticket to samsung about this problem. It's likely not considered a big deal to warrant an immediate update, so a fix may roll out with android 4.2.1.