Error SBL-STJ-00138 when adding language PTG to existing Network Image

 I am attempting to add languages ITA and PTG to an existing Siebel Install Image and I am getting the error No products found(SBL-STJ-00138)

Any ideas how to get around this issue; the existing image includes languages ENU, ESN, DEU and FRA. I need to add ITA and PTG but the Image Creator will not allow me to do this. The media packs for these two languages have been downloaded and unzipped to the same directory as all the other JAR files.

Thank You