I had the same problem at the start…the twice images and those strange lines haha…
The error is at input raw binary data, see my screenshots. It is for stripmap (pp1 because HH and HV) but its exactly the same for IW (if it is VV VH change to pp2).
Do like this, and I assure it wont occur. But trust me, results in IW are not very good, because of resolution.
Try!
Aridane