Black dots in the window depending on window style

[Cl9]

I'm pretty sure that this is in the right section of the forums... I was a little unsure?
But anyway:

Today, out of the blue, a program which I've been working on starting doing this when I started it:
Window creation code:

sf::RenderWindow window(sf::VideoMode(600, 400), "Main", sf::Style::Close);

After playing around with the window for a bit, I found that removing the style code returned it to normal:
Window creation code:

sf::RenderWindow window(sf::VideoMode(600, 400), "Main");

There's been no changes made to the computer, (no new software, drivers etc) and the source was not modified between when it was working properly and when it starting showing the dots.

The GUI aspects of the program are drawn through SFGUI but even if I create a rectangle and draw it directly, it is still affected.
Anyone have any possible reasons for why it could be doing that? Because I'm a little confused?

OS: Windows 8.1
Graphics Card: Integrated (AMD 64Bit processor)
SFML Version: About 2 weeks old from the github

[eXpl0it3r]

What kind of display do you have?

[Cl9]

Err... LCD I'd guess?
It's a laptop.

[eXpl0it3r]

Is it a high DPI display?
Or if you don't know, which laptop do you have?

[Cl9]

It's a HP Pavilion dv6-6000
Display res: 1366x768

[Mario]

That's looking really weird. Are you sure it's not the driver or somet third party program trying to modify the window frame or something like that?