This error is caused by a deficiency in the Mendix 2.* database synchronization algorithm, which has been solved in the completely rewritten algorithm in Mendix 3.0. As a work-around, it is most convenient to add the four columns manually to the table in the database (not in the model). As Samet says, they aren't all of type int32. Create the following columns:
It does not matter whether there are zero or more rows in the table.