in subreport, add a formula like:
shared numbervar totHours := the total value that is being displayed
in the section expert for the section that Correct is in for the suppression formula:
shared numbervar totHours;
totHours=0 and {wo open}=0 and {wo requested}=0 and {wo completed}=0
As for each item being suppressed if it is 0, just go to format field/general tab/ suppress button
the field will change, but the logic is the same for all of the fields
{field to suppress} = 0
for the subreport field, it would be:
shared numbervar totHours = 0
hope this helps