The transaction size is 1160 bytes. The price per 1000 bytes is 0.0005 BTC. Shouldn't you have paid 0.001 BTC fee for this transaction?
Correct me if I'm wrong.
You are correct on the price per KB. What I'm not sure of is if a 1160 byte transaction is considered 2 X 1000 bytes, or just 1 X 1000 (where remainders are not considered for the fee assessment).
A transaction will be sent without fees if these conditions are met:
It is smaller than 10 thousand bytes.
All outputs are 0.01 BTC or larger.
Its priority is large enough (see the Technical Info section below)
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http://en.bitcoin.it/wiki/Transaction_feesSo this transaction had an output below 0.01 BTC thus there did need to be fees paid at the rate of 0.0005 BTC per KB.
Incidentally, this transaction has since confirmed.