Question about US unemployment statistics

[Tender Branson]

From March to April, the US unemployment rate increased from 9.7% to 9.9%.

But now look at this table:

http://www.bls.gov/web/laus/laumstcm.htm

It shows the change in unemployment rates in every state from March to April, and almost every state had either a decrease from March or the same rate as March, especially the big states.

Both the national and state rates are "seasonally adjusted", therefore they use the same criterias.

So, if this is the case and almost every state saw a drop in the rate between March and April, why did the US rate increase by 0.2% ?

[Bo]

Maybe there are certain errors in some of the data? Sampling could be a little off.

[phk]

Probably discrepancies in the size of the labor force assuming they aren't using different methodologies altogether.