Bitcoind doesn't add miner fee How do I make sure bitcoind's RPC call sendtoaddress adds miner fees to transactions?

Tried adding to our bitcoin.conf file:
mintxfee=0.0001

But some of the transactions still won't get any miner fee attached, causing payments to take hours or days to get confirmed.
The correct configuration parameter is: paytxfee=&lt;amount&gt;, where &lt;amount&gt;is the amount (fee) per kB to add to your outgoing txs