I'm using EclipseLink with MS-SQL Server 2005.
I made the driver configuration and test connection is ok.
When starting an EntityManager, the eclipse is lock. Debugging, I found that called metaData.getUserNamee (), performed in DatabaseAccessos.buildConnectLog, is seeking input from the database. On the monitor database, the process is to "AWAITING_COMMAND" if I kill the process, the eclipse is released.
Do you get the same issue if you call getMetaData.getUserName() on the JDBC connection - try obtaining the connection from the DriverManager or datasource pool directly. What EclipseLink database config settings are you using, and how are you verifying that the connection is ok?
You might want to try different database drivers and see if there are more recent ones available that might resolve the issue.