The balance became less while voting at block 1720344:
>> blockchain_get_block_transactions 1720344
[[
    "e102d6eb0548991d403ec5c76f192469bc351faf",{
      "trx": {
        "expiration": "2015-02-06T17:57:24",
        "reserved": null,
        "operations": [{
            "type": "deposit_op_type",
            "data": {
              "amount": 136891179999,
              "condition": {
                "asset_id": 0,
                "slate_id": 1832704065200434438,
                "type": "withdraw_signature_type",
                "data": {
                  "owner": "BTSEnUYHEkFKX31A97VKyf7TvjZJZHHCLNmV",
                  "memo": {
                    "one_time_key": "BTS5NQPijZu4kw9hFjsAdY2R1trLjRmnpAs2cWgvrRB2ekyeuJYzv",
                    "encrypted_memo_data": "6bb9c247b7e665c4e5c6b6e1cd6249efe66b18fee2c99cae1265d0ed0280d52d2e9e85f92f57a9e826e7d6c45ca2a1d7c597243e8431be3eea8ffed6eb760530"
                  }
                }
              }
            }
...
            },{
            "type": "withdraw_op_type",
            "data": {
              "balance_id": "BTSH3F7MrM6fgavoAdJVXvHiqUxdVF7ZCkL2",
              "amount": 136891189999,
              "claim_input_data": ""
            }
          }
        ]
So there must be something happened at that address between block 1670016 and 1720344. Maybe another short operation(s)?