<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />Can anyone suggest a way to disable the automatic (and mandatory?) annotation that appears on every One-Way plot stating the number of "Missing Rows"?? I understand why it is there -- it tells me how rows of data were omitted in plotting my data, but most of the time I don't need this information and it just clutters the plot and raises questions from people when presenting this real-time. (Please refer to image below for example "Missing Rows" annotation).

As you say, the annotation is there for very good reasons.
You can always remove parts of any report via JSL with this kind of approach:
dt = Open("$SAMPLE_DATA/Big Class.jmp");
// Make some missing values
vals = Column(dt, "height") << getValues;
vals[J(10, 1, RandomInteger(1, NRows(vals)))] = .;
Column(dt, "height") << setValues(vals);
// Use Oneway
ow = dt << Oneway( Y( :height ), X( :sex ) );
// Delete the required part of the display tree
Wait(3);
owRep = ow << report;
// Uncomment the line below to see the display boxes that comprise the current report
// owRep << showTreeStructure;
owRep[LineupBox(1)] << delete;
More generally, you can manipulate the display tree of a report by rearranging or adding things.