Screen blinks while in grey and white combination backgrounds  

Composite sync should only be used if your monitor supports it. Do you know the model of your monitor? It may help to determine what is going on with both issues. To find the model:
1. Click Start Menu
2. Click Control Panel
3. Click Hardware and Sound
4. Click Device Manager
5. Expand Monitors (click the + next to Monitors)
6. What model is listed?

Hello! ; It just says Generic PnP Monitor :

Device type: Monitors
Manufacturer: Standard monitor types
Location: on AMD Raden HD 6800 Series
Device status: The device is working properly.

Could this be my model? (It says at the top left corner of it) Samsung SyncMaster 2053NW
I had always Composite sync disabled and it never gave me such a problem as those lines

The Samsung SyncMaster 2053NW LCD monitor is the model. If we can find a driver for it, it may fix the problem. The generic PnP Monitor is what Windows 7 uses if it does not know the model of your monitor or if your monitor does not have drivers for Windows 7. Did your monitor happen to come with a DVD or CD to install drivers?

To get the driver, follow these steps:
1. Create a system restore point in case the following installation causes your monitor to stop working correctly
2. Download the driver from El Signo (Do not click on anything on that page; as soon as the download starts, close the page. Many of the links are links to malware/spyware/etc. and you do not want them).
3. Extract the folder with 7-Zip
4. Open the extracted folder
5. Right click setup.exe
6. Click Properties
7. Click the Compatibility Tab.
8. Tick the Run this program in compatibility mode for: and select Windows Vista (Service Pack 2)
9. Click OK.
10. Run setup.exe
11. Restart your computer
12. If your monitor behaves badly afterward, restore the system restore point using System Restore OPTION TWO.

I've installed it and the drivers work fine, the lines will still appear If I disable Composite Sync My monitor didn't come with a CD or DVD.

senjougahara said:

I've installed it and the drivers work fine, the lines will still appear If I disable Composite Sync My monitor didn't come with a CD or DVD.

It is good that the driver installed properly, but it is unfortunate it did not fix the problem. Open up Catalyst Control Center and see if adjusting the desktop size/position values makes any difference.

When I move the screen the lines appear, even with Composite Sync

senjougahara said:

When I move the screen the lines appear, even with Composite Sync

Play around with stretching and scaling the graphics to fit the monitor and see if doing so helps. Try with Composite Sync off first.

No, didn't work :/

Unfortunately you are at an impasse. You'll either have to run with default settings with composite sync, or change to a lower resolution. Are you still only running into problems on that one website? If so, I wouldn't worry about it unless it starts to become more common in other situations. Your monitor is able to run composite sync safely. I believe the issue you are experiencing is due to the monitor not being Windows 7 Certified.