I experienced something similar for v0.4.23 under Linux.
Balance is 0, and there are some strange transactions.
>> wallet_account_transaction_history frodo99 BTSX 0 559676
TIMESTAMP BLOCK FROM TO AMOUNT MEMO BALANCE FEE ID
==============================================================================================================================================================================================
2014-09-23T10:14:02 559676 frodo99 SHORT-78ccb4b2 40.00000 BTSX short USD @ 0.025 USD / BTSX -0.10000 BTSX 0.10000 BTSX 360f6710
2014-09-23T11:02:00 559946 SHORT-78ccb4b2 frodo99 39.90000 BTSX cancel SHORT-78ccb4b2 39.80000 BTSX 0.10000 BTSX 0f9d4618
2014-09-28T09:41:40 602233 frodo99 UNKNOWN 200.00000 BTSX 39.70000 BTSX 0.10000 BTSX 268266ae
2014-10-05T15:27:30 664268 SHORT-78ccb4b2 UNKNOWN 3.75563 BTSX 39.70000 BTSX 0.00000 BTSX 39586b0b
Already tried importing a backup and rescanning.