I'm a bit new to the bitcoin system, so I apologize if this is a "noob" question.
A user attempts to take all the unverified transactions it knows about and aggregate them in a chain block. The same applies to all the users world wide - they all attempt to aggregate all the unverified transactions into a block chain with a 1 success every 10 minutes on a global scale rate
But - I imagine that when all the devices are trying to do this, all the devices have a slightly different list of unverified transactions, since it takes a while for a transaction to propagate to all the devices world-wide
So let's say device A and device B both create a block at the same time, when some transactions in A don't appear in B and vise-versa. Then, more block chains are created and after some time the shorter one is discarded - all the transactions which appeared as verified in the shorter block chain now become unverified again?
If this is the case, what happens to the transaction fees & the 25 bitcoin award given to the guy who created the "bad" block?
I mean, fine - the 25 bitcoin award could theoretically stay with the guy who created the block, since he did do the work, but the transaction fee? It would need to be paid to the next guy who verifies the transaction, shouldn't it?
Or in this case, would the user need to pay 2 transaction fees?