Quote from: jag2k2 on May 02, 2013, 06:12:37 PM

Receive 3.7 BTC on Address A
Receive 3.3 BTC on Address B
Send 3.25 BTC so the inputs to the transaction were A&B

Why "A&B"? Either A or B would be sufficient by itself, so there is no reason for Electrum to combine them into a single transaction. It probably used the output of the first transaction (address A), sending the remaining ~0.45 to change address C, and left address B alone.

Technically you can still receive BTC on any of your receive addresses, even ones which have already been used as inputs. Some consider it less secure because the full public key is known from the earlier transactions, as opposed to just the hash of the public key which appears in the outputs. Personally I don't think that's worth worrying over.