I am having a problem with the dirt separating from the house which is also causing my door not lock, I also heard the house settling early this morning and when I got up there was a buckling of the wall in the living room. I was thinking of buying dirt and fill up the separation around the house. Some people said the dirt just washes away. I haven't seen anymore cracks but I have noticed nail pops also. What can I do to stop this.

Do you happen to be in a severe drought area? If so, then your home is in peril from the basement caving in on the sides. You need to have a professional assess your home's damage and future damage. This may be more than a bunch of dirt being added.

Where do you live? Can you post a picture?

I live in Dallas Texas we have had no rain this summer.

Slab foundation I assume.

Yes.

During drought conditions it is best to use soaker hoses around the slab foundation or water a couple times a week around the foundation to prevent this from happening. I would get some estimates from foundation companies first and see if they include adding fill around the perimeter.
http://www.a-1engineering.com/foundationrepairscam.htm?gclid=CMbGp-H4iqsCFWNeTAodN1xXuQ

Droughts and wold fires are not helping TX right now. In your case the damage is done and your slab has moved and likely cracked. While its safeto live in this home its foundation needs professional evaulation and repair. House movers and house jacking is where I'd start in the yellow pages, get 3 bids.

Whoa, I don't know if there is enough info to justify foundation work at this point... Expensive! The buckling wall might need more explanation. Ive heard Pattys suggestion is appropriate for this because it alleviates the shrinking soils. The problem with filling soil is that once you get some moisture back in the ground it can expand which I suppose wouldn't be a big deal on a slab but not so good for a basement. Your locking problem should be easy to adjust. All slab foundations crack, its when that crack is over 1/4" and seems to be growing that its time for professional evaluation.

"Needs professional evaluation" I stand by that. All concrete does crack but the op described movement in the home, this is no hairline.

Perhaps, but without visual evidence its still hard to know for sure. I suspect this is happening all over TX right now and it will be tough to get the attention and Free evaluation of an independent party. I would get the opinion of an independent structural engineer if the contractors advise repair. This of course will cost you money unless you happen to know someone.