Thanks guys, very helpful.  Have managed to get two parcels far as 'process later' so I can do a few more, although the site is still not working on Firefox. 

It just seems like there are so many things you have to get absolutely perfectly - maybe it's just me but I don't find it as user friendly as I think it should be.

Incidentally, I asked the Australia Post lady today if she knew how Click and send worked and she said no.  But it was interesting that she did say that she's a friend of Aus Post on Facebook and the number of complaints about Click and send are phenomenal. . . . so perhaps it's not just me!