为何只打出27行？(100分)

......
     For TmpI:=Num to sGrid.RowCount-1do
 
     begin
       Inc(Num1);
       Y1:=150*Num1+300;//TmpI
       Y2:=150*(Num1+1)+300;//TmpI
       TR:=Rect(X1, Y1, X2-10, Y2);
       Printer.Canvas.Rectangle(X1, Y1, X2-10, Y2);
       Printer.Canvas.TextRect(TR, X1+20, Y1+20, sGrid.Cells[F, TmpI]);
       If F = sGrid.ColCount-1 then
       begin
         Printer.Canvas.MoveTo(X2-10, Y1);
         Printer.Canvas.LineTo(X2-10, Y2);
       end;
       if TmpI mod 27=0 then
 ****把27改为大于27的数就不行，小于等于27的数则正常********
       begin
         bNewPage:=True;
         Printer.Canvas.MoveTo(X1, Y2);
 
         Printer.Canvas.LineTo(X2-10, Y2);
         Break;
       end;
       j:=TmpI;
     end;
.................