SQL Server Leaked Transactions
There is a SQL command that will show OPEN transactions. (DBCC OPENTRAN)

http://msdn.microsoft.com/en-us/library/ms182792.aspx

Displays information about the oldest active transaction and the oldest distributed and nondistributed replicated transactions, if any, within the specified database. Results are displayed only if there is an active transaction or if the database contains replication information