Slider Iteration Timing Is Not Working Correctly

[xymantec]

I have found it is impossible to get 10-second iterations between slides, speed is set to 3751 and its 2 seconds too long, I do 3750 and its 2 seconds too short, I do 3750.5 and it's still 2 seconds too long, I have even tried 3750.1 and it still 2 seconds too long.