I'm with you surprime witch,we are told that time turning is extremly dangerous. I reckon that if Dumbledore allowed time and other natural events to be changed, he'd be no better than Voldemort. In his youth (his 1st century)Dumbledore obviously didn't get this and thus he help to create the Philosopher's Stone. I think he's now seen the errors of his ways and doesn't believe that anyone should be able to defy death. It's unnatural and it's exactly what Voldemort's done.

Which brings us to the v. interesting point someone made earlier: Why don't the Death eaters know about and use the time turner? Voldemorts done so much to make himself immortal, you'd think that a time turner would be a huge gun in his arsenal and would gurantee his immortality....?? You'd think that if they were gonna break into the Ministry for the Prophecy, they'd have done better to steal a time turner, go back and hear all the prophecy themselves.

Which brings me to another question: Who do you reckon was the eavesdropper?