Two complementary events combined to send the dollar lower against every currency except the Japanese yen. Last Friday's US jobs data showed employment rising more slowly than investors had expected. The slowdown encouraged investors to look for a further delay in the Federal Reserve's decision to begin taking interest rates higher. This Thursday the minutes of the Fed' September monetary policy meeting did not exactly confirm such a delay but they did nothing to make an increase look any more imminent.
Given that the main prop for the dollar has been the anticipation of that rate increase, the possibility of it retreating yet further into the future led investors to lighten their holdings. The dollar fell by two and a quarter cents against sterling and lost more than one cent to the euro. The Japanese currency fell by a similar proportion because investors felt less need for the safe-haven it represents.