It would help if you explained how you are trying to load them.
If you are using the "export" option from the contacts app to write them to a vcard file, with some phones you need to do this separately for different contact types (e.g. phone only or google contacts). So it may be that you are only exporting one group or category of contacts.
If you are doing something else, please post again and explain what you are using to export them?