The article yours says was filed at 1620 is subtitled, "Two killed after Pyongyang fires on Yeonpyeong island in first attack on South Korean land since 1953 war". Did you catch that? According to the articles author, this is the first North Korean attack on South Korean land since the cease fire in 1953.

http://www.guardian.co.uk/world/2010/nov/23/north-korea-condemned-south-korea

Then THIS Guardian article:

http://www.guardian.co.uk/world/2010/nov/23/timeline-north-korea-south-korea

lists a timeline of the conflict since the end of the war; the first thing it reveals is that the war hasn't actually ended, and the next three entries are North Korean attempts to assassinate the South Korean President (though I concede one of them occurred in Burma, last I check Seoul was still in South Korea).

"27 July 1953
The war ends when North and South Korea sign a truce – but there is no formal peace treaty, meaning the two countries remain technically at war. The Korean war cost 2 million lives.

January 1968
North Korean commandos launch a failed assassination attempt on the then president of South Korea, Park Chung-hee.

15 August 1974
There is another assassination attempt on Park Chung-hee, by a North Korean agent in Seoul. Park survives, but the first lady is killed".

I wish people didn't try so hard to make deliberate acts of war into mere misunderstandings.