If I use the RadInputManager Validation for a given text box, and set it to required, after post back, the "EmptyMessage" behavior fails to work, and that text becomes the actual text that displays.
To recreate this situation outside of my application, I took the "Ajax" validation sample (http://demos.telerik.com/aspnet-ajax/ajax/examples/common/validation/defaultcs.aspx) and added a RadInputManager too it directly after the closing of the table:
<telerik:RadInputManager ID="RadInputManager1" runat="server">
<telerik:TextBoxSetting EmptyMessage="Enter Name" InitializeOnClient="true"
<telerik:TargetInput ControlID="tbName" />
I then removed the "RequiredFieldValidator" named "RequiredFieldValidator1" to eliminate the redundant validation.
Upon submitting the form without entering any text entered in the text box, the error message is displayed in the text box as it should, but when you attempt to enter text in the text box, you find that the text box is filled with the "EmptyMessage" text, and the user must manually delete the text before entering the desired text.