Czuch Czuckers: it has never happened to me either .. but i did come across something which might look quite similar ..

sometimes when i click on the 'roll dice' button it gives me the same dice again .. then i select the dice again and click on the button again .. sometimes it still shows the same dice after that ..

that way it might look like no roll has happened .. but in my case it was just the statistically correct chance that the dice might show the same numbers again (chance 1/6 per die, 1/36 for 2 dice)