That is a very small amount of people to sample compared to the number of people in the US. Its a much smaller percentage than the economist poll that IA Obama supporters wanted to ignore. Seems that Obama supporters have a lot of difficulty holding everyone to the same standards yet they want to claim that they are looking for fairness all the time.
As to the numbers I suspect that they are correct. Plenty of people that used to have high paying full time jobs have been forced to take part time low pay jobs to survive and the reports have noted that for quite a while.