I suspect a large part of the problem is that ebay are putting unrealistic delivery time estimates on listings and encouraging buyers to claim if the item does not arrive within the estimated period. This is particularly noticable with international sales. These are the larger proportion of my problem, but I am still getting Australian claims too.

I suspect many buyers genuinly have not got the item when they claim, due to Australia post or international customs delays, but they are unwilling to wait a reasonable period to see if it turns up. I refund to avoid a defect and no doubt many buyers recieve their item a few days later. Result one happy ebay buyer and one ripped off seller.

I suspect many buyers can see they will get the item for free once the claims process has begun and dont notify ebay or the seller when it does turn up, even if it is before the dispute has settled.

Ebay are effectivly training buyers on how to abuse the system and steal from sellers by using unrealistic postage time estimates and encouraging buyers to claim "item not recieved" if it does not arrive within their unrealistic estimated delivery times..