Payrolls shrank, and unemployment rate went down because the overall labor pool, or the people who the census counts as being either employed or unemployed shrank. In other words, more people left the work force, most likely due to the fact that they have not been able to get a job for a series of months, and therefore have been taken off of unemployment benefits, and are moved out of the labor market.
My guess is that if the requisites for the census was changed so that unemployment figures also account for people who have just given up looking for jobs or those who are just out of college and never had jobs, the actual unemployment rate would be much higher, probably closer to 11% or so. At the last meeting between bernanke and state/senate representatives, several of those representing the western or southern states indicated unemployment rates including those who have not been able to secure work for 12 months or over is dramatically higher then the national unemployment rate.
The overall picture is starting to become more similar to what Japan is going through. Japan states the unemployment rate at 4.1%, but does not count house wifes who make up a good portion of japanese women(most of those who are married tend to become housewifes), does not count college students who graduated and have not been able to find work due to Japan's stagnate economy, or those who have not been employed for 6 months or more. On the outside Japan likes to keep a rosy picture of how healthy the country is, but many signs are fairly obvious when 4 or 5 generations of one family is living in the same house, with usually only one or two members providing income for the entire household.