Strange horizontal tails in my Samsung 2032NW

Hi. I am a filmmaking student, oriented to the photography and camera area, and also do some editing. I have my computer (a Hackintosh) with many programs for color correction, I bought it about a year ago.
I have this Samsung 2032NW LCD display, which was pretty well calibrated for color correcting (although it's not the best, I know).
Some weeks ago, maybe a month ago, I started noticing some weird horizontal tails, which are like a gradient to the right of any white thing.
To show an example, I drew a grey square with 2 horizontal bars. (link to picture below). Both are the same white level, but the upper one is longer. As you can see, both of them generate a gradient tail to the right. The first bar is longer, so it generates a stronger tail.
http://www.rodrigocine.com.ar/monitorgradient.jpg

In the screen, live, it's more noticeable than in the pics I got with a cheap video camera
It's very annoying to have those lines all over the screen when trying to concentrate in an image. Mainly if I am doing the color of a scanned short film and the Director of Photography is besides me asking "what are those lines in the picture?". I explain them (and after tests, I see that this doesn't really affect the image, when watching it later in another computer or TV), but it's not nice.
http://www.rodrigocine.com.ar/color.jpg

I would like to know if this is part of the normal tear of a TN-panel LCD monitor, if I should complain to Samsung (it has a 3-year warranty, but I don't think they'll accept this). My computer is besides the monitor, I am in a very small room. Can it somehow be affecting it (with interference or something)?
Or maybe it's me, maybe the lines were always there and I am noticing them now :S.

Hope you can help me,
Thanks!
Rodrigo

P.S: I know I should get a better monitor for color correcting... but this is what I have now... And currently I don't have the money to buy something professional (I live in Argentina.. things are more expensive here...).