Outbound item (Laptop) held in US Customs!!?

I ordered a Laptop from an online shop from USA which was being delivered through USPS. They picked it up on March 17, 2010 and since March 18, 2010 the tracking showed "Sent to U.S. Customs by U.S. Postal Service". Now today (March 28, 2010) a new update was added "Held in US Customs". So my question is:



1- Why an outbound item is being held in custom. (I know for sure that there is nothing illegal about this item as I bought it from one of the most reputable online shops).



2- How long will it remain there?



3- Is there some process to get it released? Or is there anything that can be done to expedite the process? Can the store who has sent me the item help in this regard?



I am really worried as this is the first time I am buying something online from USA. Any sort of help will be appreciated.



Here are the details of tracking.



------------------

Label/Receipt Number: ECXXXXXXXXXXXX

Class: Express Mail International庐

Service(s): Insured

Status: Held in US Customs



Your item is being held in US Customs for further inspection.



Detailed Results:

Held in US Customs

Sent to U.S. Customs by U.S. Postal Service

Processed through Sort Facility, March 17, 2010, 7:00 pm, OMAHA, NE 68110

Processed through Sort Facility, March 17, 2010, 3:08 pm, LINCOLN, NE 68501

Acceptance, March 17, 2010, 10:03 am, LINCOLN, NE 68507

Electronic Shipping Info Received, March 17, 2010

------------------Outbound item (Laptop) held in US Customs!!?
It depends on where you are. It is illegal to export electronics to some countries, so if you are in Iran for example, you will be waiting a long time. If you are in Canada, it should be days. The USPS service was probably the wrong way though. Fedex for example would be much faster and would pass customs more quickly, though you will still pay the same duty if applicable.Outbound item (Laptop) held in US Customs!!?
I purchase clothes from China all the time, and every time they are shipped here to the U.S. it always says it's being held by customs. This usually lasts for a few days, then it's released.