Problem mit sleep

[hathor]

Delphi-Quellcode:

procedure DelayQPC(t: cardinal);
var  a, b: Int64;
Begin
    QueryPerformanceFrequency(b); QueryPerformanceCounter(a);
    b := a + (b * t) div 1000000; //10 000 = 0.1ms, 100 000 = 0.01ms, 1 000 000 = 0.001ms
    While a < b do QueryPerformanceCounter(a);
end;

Aufruf: DelayQPC(1000); // 1 msec
        DelayQPC(10000); // 10 msec