Dataset.WriteXml Method writes an additional table instead of overwritting

Question

I have a dataset in my hand with one table only and I want to write it to the current xml file. When I write it, it creates a new table and add it to it instead of overwritting. everytime I write it, It multiples the number of tables by 2.

Globals.ds.WriteXml(Application.StartupPath + "\\Settings.xml");

How do I overwrite to the same xml file to save the parameters?