ASP.NET Textbox AutoPostBack Not Firing

[V_I_R_U_S]

After searching I've found a number of suggestions, but none of them are fixing the issue. \[code\]<asp:TextBox runat="server" ID="uid" AutoPostBack="True" Text=""></asp:TextBox>\[/code\]In the properties window, EnableViewState = True for the TextBox (Suggested here). I am typing a new value into the TextBox and then hitting the Tab key. Nothing happens nor does the break point at if(IsPostBack...) break.Code Behind:\[code\]protected void Page_Load(object sender, EventArgs e) { if(IsPostBack && uid.Text != "" && pw.Text == "") { Do stuff } }\[/code\]