But hold on a sec - weren't crude prices supposed to be headed down in the face of a slumping economy and lower demand? Fooled again! Light, sweet crude for March delivery jumped $4.51 to settle at a record $100.01 a barrel. Oil has never before closed over $100, though when adjusted for inflation, the price is still slightly below the highs set in early 1980. As you might expect, various explanations are being offered for the runup - a refinery explosion in Texas, a possible cut in OPEC production, ongoing tensions between the U.S. and Venezuela, the dollar dropping, blah, blah, blah. Here's the truth: nobody knows nothing. James Cordier, founder of OptionSellers.com, a Tampa, Fla., trading firm, told AP that the oil market is in the process of ''decoupling'' from supply and demand fundamentals. All of which means you shouldn't be surprised if oil goes back down. Meanwhile, L.A.-area gas prices have shot up 8 cents in the past week, according to the government's just-released survey. The average price of regular is $3.161. That may or may not have anything to do with the higher price of crude.