WPF switching column visibility in DataGrid triggers unwanted event

I have a weird issue where changing data grid column visibility with a press of a button, it triggers a "Checked" event tied to a checkbox in that data grid column.

So here's my setup:

• I have a label (lblUpdateMode) with a text either "single row" or "every row";

• A datagrid with 10 columns, where initially 5 columns are visible and 5 are hidden;

• Pressing a button (btnChangeView) flips visibility of each column;

• In one of the data grid columns I have a CheckBoxColumn, with Checked/Unchecked events. If label text = "every row" pressing on a single checkbox updates every row.

However, if label = "every row" and I press on btnChangeView, it also triggers Checked event and updates checkboxes in every row.

Why is this happening and how can I avoid it?

Here's the code to the Checked event - nothing fancy or strange:

private void UpdateDataGridCheckBox(string colname, bool v)
        {
            if (lblUpdateMode.Content.ToString() == "Every Row")
            {
                foreach (DataRow dr in DataAccess.Instance.sourceFiles.Rows)
                {
                    dr[colname] = v;
                }
            }
        }

Thanks