A tiny annoying problem.

When I plug in my headphones on my new computer there are some weird things that happen. When I play games the sound is fine, but there is a crackling in the background. This does not happen in desktop. When I scroll up or down on a page its starts crackling as well, but if I scroll the scroll wheel on something that doesn't scroll nothing happens. It also crackles if I drag the scroll bar. Its not that big of a problem but It is really annoying.

My sound is integrated in my ASUS P5QL PRO P43.

Can someone suggest a solution.

UPDATE:

My speakers, (which are plugged into the back panel) have a headphone jack in them. When I plug my headphones in that jack they don't make the sounds, but still work. It is something with my connecters.

My computer has a Legacy connector and a HDA connector. My mobo supports both. Later I will put in the legacy to see if that helps.

Do you see what could be the problem?