When I updated Bitcoin Wallet on my Android device, it automatically created a new address and transfered all my funds from my old address to it due to the recently found security issue in Android's random number generator.
However, it didn't do it with a single transaction. Instead it did two transactions, so I had to pay the transaction fee (0.0001) two times.
Did it perhaps split it into two smaller transactions to keep the size down (only a guess) for the sake of the network? Or is a smaller transaction processed faster? Or was this necessary for completely emptying the old address? Or was my old address fragmented after multiple transactions to and from it in its history (if that is even a thing/possible)?
My questions above are only speculation. And my real question is: is it sometime advantageous to do two (or more transactions) to the same destination instead of a single, big one?