存储过程通过Java运行速度比直接在数据库上运行慢30％

I'm using Java 1.6, JTDS 1.2.2 (also just tried 1.2.4 to no avail) and SQL Server 2005 to create a CallableStatement to run a stored procedure (with no parameters). I am seeing the Java wrapper running the same stored procedure 30% slower than using SQL Server Management Studio. I've run the MS SQL profiler and there is little difference in I/O between the two processes, so I don't think it's related to query plan caching.I'm using Java 1.6, JTDS 1.2.2 (also just tried