C# :: TextBox Navigation Using Arrow Keys

So I have assigned this method to each TextBox. It works fine pressing the left arrow and right arrow, but for some reason will not work using the up and down arrows. I have tested the string, using MessageBox and it is correct...the loop even proves it finds a matching TextBox. It is correct as in it displays the TextBox name it should be selecting but doesn't. I have no clue! Now the first select method is the one I want to use, I used the loop to check to see if it was even finding a match. It does find it but doesn't select it. The naming convention for my text boxes is r1c1 where the first number indicates the row and the second number is the column. There are 9 rows and 9 columns. This SHOULD be working but for whatever reason it is not. I've even put a message box inside the if statement for the up and down keypress check and it pops up when i press up or down.

private void Navigate(object sender, KeyEventArgs e) {
TextBox input = (TextBox)sender;
string nextBox = input.Name.ToString();
if (e.KeyCode == Keys.Left) {
if (int.Parse(nextBox.Substring(1, 1)) > 1 && int.Parse(nextBox.Substring(3, 1)) == 1)

[Code] ....