是什么导致SQL Server返回消息'语句已被终止'？

I have a very simple INSERT statement being executed from a PHP script running on a Linux Apache web server. I can run the query fine from within SQL Management Studio and it normally runs fine from PHP as well. However, every once in awhile I get an error message from my PHP script that the query failed and the mssql_get_last_message() function returns 'The statement has been terminated'.I have a very simple INSERT statement being exe