I expect that when I send money using the top menu entry to do so, the program is smart enough to give me at least the possibility to add a fee, which it didn't.
So when the coins came back I sent 0.01 BTC to see if I overlooked something and had a possibility to add the fee, which I had not. Only then I found the send special menu item which allowed me to add a fee. I used that to send 0.1983 + 0.002 fee. But why should now a transaction with a fee be combined with one without a fee and combined with one without a fee and treated as if no fee is added.
If BTC want to be a mainstream currency system these things have to change.
It's just the way bitcoin works. You need to wait for the "change" from your first transaction before the second transaction can be sent. So basically, your second transaction is stuck in a queue behind your first one.
You're right about the "special menu" on blockchain.info, they should make it more obvious. You're certainly not the first person to make this mistake using that site.
Don't worry, it'll all go through soon enough. Live and learn.