So what is the recommended transaction fee to input manually to guarantee this does not happen? This is making me scared to make transactions now.
0.0002 here
0.0001 gets me very high priority on most of my transactions. If they were higher value Tx, I would include more of a fee.
I use BC.I quite a bit and have not had the OP's problem. However, I read a similar thread several months ago that described a similar issue. I have paid VERY close attention since then.
This was likely OP error all the way. If the OP can track the miner down, I'm certain he will get a refund. We bitcoiners are like that.