There has been a heated debate between the US and Canada over the tariffs being assigned to softwood imports into the US. In 2002, the US implemented these tariffs, which are reportedly contrary to the NAFTA agreement. [Note: Sub.]  A 3-person arbitration board ruled that the US must refund over $5B in tariffs collected from imported Canadian softwood.  The US lost the appeal on the ruling but still has refused to refund tariffs already levied.
There has been a lot of controversy surrounding the softwood tariff debate. Canada exports more than 50% of the lumber they produce to the US and the US will need more lumber as a result of Hurricane Katrina and the on-going housing boom. Look for rising prices for construction supplies as a result.
[Casper Star Tribune] 
[National Post] 
The housing boom has placed a significant pressure on the availability of lumber for construction. Wood exports from Canada are a significant source of lumber for the US and a major export of Canada.
In light of Hurricane Katrina’s extensive damages to the gulf area housing stock of Lousiana, Mississippi and Alabama, demand for construction supplies are expected to increase significantly and at least one advocate for affordable housing wants the tariffs removed. 
Lets hope these two allies and neighbors can resolve their differences and get this crises resolved soon.