Oil dropped below $145 a barrel Tuesday in Asia although a series of threats to supply in a finely balanced market continues to keep a floor under prices. "The oil market right now is fundamentally tight, which is why prices have been high and volatile," said David Moore, a commodity strategist with Commonwealth Bank of Australia in Sydney. In midday trading in Singapore, light, sweet crude for August delivery was down 26 cents at $144.92 a barrel in Asian electronic trading on the New York Mercantile Exchange. The contract rose 10 cents in Monday's floor session to $145.18 a barrel, just over a dime short of the all-time settlement high. Threats to supply in Brazil, Iran and Nigeria have been keeping oil near the record levels hit last week. ...