Thanks for your reply. The Sony files I am trying to load are from a client and I do not have the voice stick you refer to.
I have just lost more than 3 hours working time attempting to load a 2MB file. After more than 3 hours it was not even 40% complete - the load was therefore going to need more than another 3 hours, resulting in the equivalent of ONE DAY to load one file, which is totally unacceptable.
My solution: uninstall the latest version and revert to an earlier one. Success - it look less than a minute to load the same 2MB file. Until the latest version of the software is reliable for Sony files I'm sticking with version 4.02.