The 2.0 TextBox control has no visualization of text selection. It does not matter if you select the text programmatically or with the mouse. My testing shows that the text is indeed selected but the UI does not convey this to the user. This occurs on a default TextBox control with no CSS stylings, skinning, etc. I have not tried adding CSS stylings to workaround this problem. A sample application that demonstrates this problem is attached.

Thanks!
Kyle