Let us know if you placed a duplicate order. We can cancel one of them for you.
We are allowing different customers to pre-order the same domain name. Each customer who wants a domain should get a shot at it.
Of course for the popular domains the chance of actually getting the domain will be low. There will be competition from other Dynadot customers, as well as competition from other registries.
Placed a preorder and paid for a idn .biz twice by accident ;-(