I have had the same problem with 3 500 gram satchels now, They don't all do it most scan through fine and it seems to be completely random as there is no link with their addresses, they're all in different states. I haven't had a problem with 3kg satchels yet thank goodness. That would be very annoying because the cost to post those parcels with other methods is quite a bit more expensive than eBay satchels.