Well, not sure what you are experiencing. I do not hear them. Try this test.
1. With everything stopped, Clear the RMX multi (from the Utility Menu).
2. Load the 150-Super Thin Ride into part 1.
3. Play the part in RMX using the Part Play button - Still hear "bleep"?
4. If so, stop RMX. Play the slices from your midi keyboard while in SLICE MENU mode.
The notes start at C2. Play chromatically and identify which notes/slice(s) have the "bleep".