Fortran bug?

[John Chee Wah]

Here is a piece of code (isn't mines) that I think should work. Loops and
goto ends with a single continue statement. The program will work if the
two loops have separate statement labels.
System is 4D/240 with 3.2.1.
-----
      write(6,'(''Enter integer 0 or less and program will loop: '',$)')
      read(5,*)iup
c
      do 1 i=-1,1
         if(i.gt.iup)goto 1
         do 1 j=-1,1
            write(6,'(''j='',i4)')j
 1    continue
c
      stop
      end