Recently placed an order (13/8/10) with an overseas supplier and sponsor of another forum and waited patiently for the goods to arrive.
As patience grew thin I made some enquiries to supplier and was informed "must be with customs, wait a bit longer"
Waited, called MAF, customs, NZ post ,Oz post, nothing to indicate the goods arrived in NZ.
Contacted supplier,"give it another week, you chose not to insure the package, as per our t&c's we're not responsible".
Bottom line, take the insured option, it would have made the purchase twice as much as the goods cost but you have some come back if things go wrong, don't think an ozpost reference number will help you.