EMC Manual Moves

I have a question about using EMC in manual mode. Suppose I wish to
move the X axis .1 inch using the keyboard right arrow key. If the
feedrate override is set high, hitting the key and letting go will
cause the axis to move the required distance. But when the feedrate
override is set to about 20 if I do not hold the key down until the
move is finished it will stop at some distance less than .1". Is this
supposed to be this way? None of the shareware cnc programs I have
tried act this way, but I have never used a commercial cnc program
before and am unsure if this is right.

I am using steppers, November ?? version, and the tcl/tk interface. I
guess I should try the other older interface to see how that acts.

thanks
bill