unfortunately, that post isn't much help. It's actually less detailed than the other 2 tutorials already referenced here. And further, it doesn't describe the symptoms that we are experiencing. Following these instructions we are seeing the the SPID sits in an endless state when SSMS goes to test the linked server connection. Killing the SPID then even puts the SPID in an endless KILLED/ROLLBACK state. Clearly, this is either some kind of bug in MSSQL Server, or the MySQL ODBC driver. Either way, there doesn't seem to be a whole lot of people that have encountered this as far as my searching can tell...