i'm rusty, but don't you have to provide a seed value somewhere to get different values each time through?
If you seed the Random number generator with the same seed every time, you will get the same sequence of numbers:
Random sequence = new Random(100L);
However, the default constructor for Random uses the current system time for the seed:
Random sequence = new Random();
which should produce a unique seed unless you create two Random objects in a row and the code executes so fast that the system time hasn't changed.