SQLContainer with MSSQL addItem/getItem mismatch bug

I am new to Vaadin, but pretty sure this is a bug.  The ID returned by SQLContainer.addItem() cannot be used for a subsequent getItem() call.  Maybe this only bites with an "identity" type primary key, but using an identity key is a common pattern, and SQLContainer seems to explicitly try to support it, in general.  I believe the problem is related to what is returned by addItem(): the RowId returned does not contain the same value type as what is returned by getItemIds().

Table:

CREATE TABLE bugDemo(
    [id] [int] IDENTITY(1,1) NOT NULL,
    [version] [int] NOT NULL default (1),
    [someOtherproperty] varchar(20) null,
 CONSTRAINT [PK_bugDemo] PRIMARY KEY CLUSTERED 
(
    [id] ASC
) ON [PRIMARY]
) ON [PRIMARY]

Code to illustrate the problem:

private void showProblem(Layout layout) throws SQLException {

        final TableQuery demoTable;
        JDBCConnectionPool pool = new SimpleJDBCConnectionPool(
                "com.microsoft.sqlserver.jdbc.SQLServerDriver",
                "jdbc:sqlserver://localhost:1433;databaseName=vaadinExercise;",
                "foo",
                "bar"
        );
        MSSQLGenerator gen = new MSSQLGenerator();
        demoTable = new TableQuery("bugDemo", pool, gen);
        demoTable.setVersionColumn("version");
        SQLContainer container = new SQLContainer(demoTable);
        container.setAutoCommit(true);

        Object newKey = container.addItem();
        Object newKeyValue = ((com.vaadin.data.util.sqlcontainer.RowId)newKey).getId();
        layout.addComponent(new Label("added new item, ID=" + newKey + "," + newKeyValue[0].getClass() ));

        Collection<?> itemIds = container.getItemIds();
        Object oneKey = itemIds.toArray()[0];
        Object oneKeyValue = ((com.vaadin.data.util.sqlcontainer.RowId)oneKey).getId();
        layout.addComponent(new Label("but the class of item IDs in the table is " + oneKeyValue.getClass()));

        Item addedItem = container.getItem(newKey);
        if (null == addedItem) {
            layout.addComponent(new Label("Therefore, you cannot retrieve the item you just added!"));
        } else
        {
            layout.addComponent(new Label("But you can retrieve the item by the key, anyway"));
        }
    }
}

Output:
added new item, ID=4,class java.math.BigDecimal
but the class of item IDs in the table is class [Ljava.lang.Object;
Therefore, you cannot retrieve the item you just added!

I ran into this using Vaadin version 7.4.5, and reproduced it again in version 7.5.0.  Using sqljdbc41.jar from Microsoft.

Any advice?