Do I have a foundation problem or is it normal settling?

My celing in the southeast corner and northwest corner of my house seems to be coming apart. The house was built in 2002. The celing about 3 feet out from the wall slopes down to the wall. All the nails/screws that were taped and puttied have popped all the putty off and you can see the drywall tape now. Is this normal settling or could I have a severe foundation problem?