SQLCommand's Transaction Property Goes Null On Failure

I've written some provider independent code that dynamically generates and loads DbCommands with data via Parameters and executes them within a transaction. Everything works fine until an exception occurs and then the DbCommand.Transaction property that was set goes to null,  effectively killing any chance of rolling back the transaction. I've noticed this only happens when the executed command is of type SqlCommand. The OracleCommand mainitains its link to the set transaction of failure. Upon further investigation, I found that this only occurs when parameters are used but not if I dynamically generate the insert statement as a string.. For instance:
SqlConnection conn = new SqlConnection(connectionString);
conn.Open();
SqlTransaction transaction = conn.BeginTransaction();
SqlCommand comm = new SqlCommand();
comm.Connection = conn;
comm.Transaction = transaction; 
command.commandText = "INSERT INTO Table1 Values (1, 2, 3)";
command.ExecuteNonQuery(); 
If I execute that and it fails the command.Transaction property will remain set to transaction, but in this scenario:
 
SqlConnection conn = new SqlConnection(connectionString);
conn.Open();
SqlTransaction transaction = conn.BeginTransaction();
SqlCommand comm = new SqlCommand();
comm.Connection = conn;
comm.Transaction = transaction; 
comm.commandText = "INSERT INTO Table1 Values (@Col1,@Col2, @Col3)";
comm.Parameters.add(new SqlParameter("@Col1", 1); 
comm.Parameters.add(new SqlParameter("@Col2", 2);
comm.Parameters.add(new SqlParameter("@Col3", 3);

 
comm.ExecuteNonQuery();
 
Upon failing the comm.Transaction property gets somehow goes null and the Connection property of the transaction object also goes null.
Any ideas on why this only happens with a SqlCommand but no other DbCommand?