Thanks - I've given that a try but it's inflating the files further still!!
I have found another one for about $9 (
faststudio) which - on the 50% file it output cut the size dramatically - but so far I have attempted to purchase it using both paypal and credit card on two separate days with no luck!
I've emailed them twice now.
You wouldn't think it was so hard to legitimately use the software would you!!