I just came across something strange, block no 289791 which was mined on Mar 10, 2014 is empty of any transactions. Is it because the miner refused to accept any? Or something else?
This is the previous block,
289790 Number Of Transactions 86 Height 289790 (Main Chain) Timestamp 2014-03-09 23:24:02 Size 43.853 KB
This is the block you are talking about
Number Of Transactions 1 Height 289791 (Main Chain) Timestamp 2014-03-09 23:30:23 Size 0.183 KB
As you can see by the size of the previous block, there was little activity in that time, only 43 KBs worth of transactions, you can also note that both blocks came less than 5 minutes apart, so perhaps the transaction pool was emptied by the previous block and there wasn't enough time for a new transaction to be broadcasted after that. Since every minute counts, miners won't wait for a new transaction to appear because they run the risk to lose the block reward.