I am trying to filter a datagridview with a date range. I found a site that had the syntax but I cannot get the filter to work. I don't get an error but I don't get the records I should, either. Here's my code:

        private void btnLocOfficeNotes_Click(object sender, EventArgs e)
        {
            string filterON = "";            
            DateTime begDate, endDate;
            bool testDateOK = DateTime.TryParse(this.mtxtBegDate.Text, out begDate);
            if (testDateOK)
            {
                if (!mmType.IsEmpty(filterON))
                    filterON += " AND ";
                filterON += "EnterDateTime >= '" + begDate.ToShortDateString() + "'";
               //Add hours and minutes to make sure that I get all entries for the end date, regardless of time
                if (this.mtxtEndDate.Text.Substring(0, 3) == "  /")
                {
                    endDate = begDate.AddHours(23).AddMinutes(59);
                }
                else
                {
                    testDateOK = DateTime.TryParse(this.mtxtEndDate.Text, out endDate);
                    if (testDateOK)
                        endDate = endDate.AddHours(23).AddMinutes(59);
                }
                filterON += " AND EnterDateTime <= '" + endDate.ToShortDateString() + "'";
            }

            DataTable dtON = (DataTable)oOfficeNote.GetCurrentDataSet().Tables[0];
            dtON.DefaultView.RowFilter = (filterON);
            dtON.DefaultView.RowStateFilter = DataViewRowState.ModifiedCurrent;

I used the dates 9/30/2008 - 10/01/2008 and there were definitely records meeting the criteria but I get an empty grid when I try it. I also tried this using # rather than single quotes as delimiters for the dates, but that didn't work either. Any ideas? Thanks.