We have had problems with RadMaskedTextBox showing the EmptyMessage since upgrading to 2012 Q2. Previously this was not a probhlem. The following markup just shows the expected input rather than the empty message.
See the attached screenshot.
<
telerik:RadMaskedTextBox
ID
=
"SSNTextBox"
runat
=
"server"
EmptyMessage
=
"SSN"
Mask
=
"###-##-####"
/>
See the attached screenshot.