Prevent Firing RowValidate/Validating Event Before A Function?

I designed a DataGridView under the name "dgvTarifa" and took a chance on trying Row Validating (tried Validated, CellEnter, CellLeave, RowEnter, RowLeave all count same) event. The purpose of the code is to load the selected values of the respective columns into three textboxes in order to rephrase/revalue those and update them by pressing a button. All works fine every single line of code there's nothing wrong except one logical thing.

When the form loads the RowValidating automatically fires because I have a function that Selects the table from the Database and it fills the DataSet by then attaching it to the datasourse of the "dgvTarifa" table. After setting the datasource of the datagridview, it automatically jumps to the RowValidating event which I DONT WANT TO! It first has to finish the whole function and later when the user enters with mouse or enters/leaves a row this has to be fired. (eventually already have the CellClick event with the same code below so only RowValidating has to work properly...)

Here's the code I use at row validating

Code:
Private Sub dgvTarifa_RowValidating(sender As System.Object, e As System.Windows.Forms.DataGridViewCellCancelEventArgs) Handles dgvTarifa.RowValidating

[Code].....