Since you have not shared your code, based on what you say, it sounds like you call the same code more than once in your program to reload your data source - as a result, the code is calling
with the same parameters. This would attempt to add a duplicate binding to the
collection - leading to error.
One solution is to clear the DataBindings collection before you add your new binding, something like:
Me.TextBox1.DataBindings.Add("Text", myDataTable, "Col1Name")