The Dot in a DataTable name or a DataColumn name will not make the DataBinding happy.
For example, if you drag drop a table from the DataSource window to a Windows Form, it would not create the right grid (the grid without columns).
This is by designer from the DataBinding perspective.
Well, our team has done some work to fix part of the problem.
For example, when you create a table with the names containing dots,(e.g. My.Name), through one of the techniques (Drag drop from server explorer to dataset designer, or by TableAdapter Wizard in the dataset designer or by going through the DataSource Wizard). We will fix the name to replace the "."s with "_"s.
However, the dataset designer would not stop user putting a "." in a table's name as it is a legal name for dataset and we are not prohibiting users to do so. That is why I said we can only fix part of the problem.
I have encountered several bugs regarding this issue and I felt that a FAQ is better addressed the issue.