DataGridView filter gives exception of 'Cannot find Column'

I have two DataGridViews that I want to filter.  The first filter works fine but the 2nd on dgvPKIENS gives me a System.Data.EvaluateException that says {"Cannot find column [SynonymF8x01]."}.  I verified tblPKIEN does have column DWTableName and column with value SynonymF8x01.

Any idea why I'm getting this exception on the 2nd filter and how to resolve it?

        private void tvFileMan_AfterSelect(object sender, TreeViewEventArgs e)
        {
            getFileAndColumns();
            //Filter dgvColumns
            BindingSource bs = new BindingSource();
            dgvColumns.DataSource = tbltAttributes;
            bs.DataSource = dgvColumns.DataSource;
            string fmfilenum = e.Node.Text;
            bool b = fmfilenum.Contains(".");
            if (b) bs.Filter = "FMFileNumber = " + e.Node.Text.Substring(0, e.Node.Text.IndexOf(" - ")).ToString();
            else bs.Filter = string.Format("FMFileNumber =  convert({0}, System.String)",
                e.Node.Text.Substring(0, e.Node.Text.IndexOf("  - ")).ToString());
            //bs.Filter = "FMFileNumber = " + e.Node.Text.Substring(0, e.Node.Text.IndexOf(" - ")).ToString();
            dgvColumns.DataSource = bs;
            // filter dgvPKIENS
            BindingSource bs1 = new BindingSource();
            dgvPKIENS.DataSource = tblPKIEN;
            bs1.DataSource = dgvPKIENS.DataSource;
            string dwTableName = tbTableName.Text.Split('.')[1];
            bs1.Filter = "DWTableName = " + dwTableName;
            dgvPKIENS.DataSource = bs1;