Brightness Problem: Increases when decreased and vice versa

Hello folks,

I'm having a problem with brightness in my laptop.
My Laptop specifications: Drop Down Menu at the left-bottom corner of this post.
It is 1 and a half years old.

If thread title is confusing, let me explain the problem in detail:

When I bought this laptop, it had a Anti-Reflective HD LED Display (which I really liked).

But a few days back, I noticed a horizontal white line blinking at the top of the screen.
The line would show up for 1 second and be gone for 2 seconds.

Then the next day I turned on laptop and noticed not only the while line blinking but also the display was jumping every 2 seconds.

I first thought it was a Graphics Driver problem, so I re-installed, but no luck. (Intel + AMD Switchable)
So I checked if display jumped at BIOS screen, and yeah, it did .

So I contacted a local Computer Repair shop and they checked what was the problem.
The problem was the Display itself. They told me the display needed to be replaced.

I agreed and replaced it with a new shiny (but reflective) display.
Brightness settings worked fine with the original display
But after replacing it, there was a small problem with brightness.

If I increase brightness, it decreases and if I decrease it, it increases.

I kinda sounds funny, doesn't it?

But there are some facts:

> Brightness acts like this in Windows only no matter from where I change it (FN Key, Mobility Center).

> I can change brightness at BIOS Screen using FN keys and it works fine there.

I even re-installed Windows using Recovery Disk provided by Samsung but problem still persists.

Any idea what could be causing this?

Sorry if there are any grammar mistakes, I'm not native.