Quote from: rigrenter on January 14, 2015, 09:21:48 AM

Hi,

I'm using bitcoinqt 0.9.3 windows and I have "0.00010000" under "Pay transaction fee". Yet still I see some transactions are sent without fees (and thus are taking extremely long to get confirmed).

Are you sure? Can you provide an example of a transaction that you sent from your Bitcoin Core wallet?

Quote from: rigrenter on January 14, 2015, 09:21:48 AM

How is this possible? Is this a bug?

Possibly, but I haven't experienced it yet.

Quote from: rigrenter on January 14, 2015, 09:21:48 AM

And another questions: do bitcoin transactions ever expire?

No, but they can become invalid if a different transaction is confirmed that spends any of the same inputs.

Quote from: rigrenter on January 14, 2015, 09:21:48 AM

If they have 0 confirmations in a particular time period?

Peers (and miners, and mining pools) can drop your transaction from their memory after a while if it doesn't get confirmed. You can always re-broadcast it if that happens. I think Bitcoin Core automatically re-broadcasts any unconfirmed transactions occasionally.