Commented Issue: MaskedEditExtender loses value [27920]

MaskedEditExtender works fine when user enters a value then exits the textbox.
However, I have a situation where a textbox is filled by code:
PhoneTextbox.Text = "6105551234" (value found in database, but is user editable)

When the textbox is displayed it is blank! Am I missing something?

Here is the Textbox definition:
<asp:TextBox ID="PhoneTextBox" runat="server" MaxLength="10" Columns="13" Visible="False"> </asp:TextBox>
<cc1:MaskedEditExtender ID="PhoneMaskedEdit" runat="server" Enabled="True" Mask="(999) 999-9999"
MaskType="Number" TargetControlID="PhoneTextBox" CultureAMPMPlaceholder=""
CultureCurrencySymbolPlaceholder="" CultureDateFormat="" CultureDatePlaceholder=""
CultureDecimalPlaceholder="" CultureThousandsPlaceholder="" CultureTimePlaceholder=""
ClearTextOnInvalid="false" >

Please help.

Thank you.

Comments: Thanks a lot for your code examples! We found the reason you get this error message and have fixed it. This fix will be available in the next AJAX Control Toolkit release (v.16.1).   I have attached a new library DLL file for you. Replace the AjaxControlToolit.dll file in your project with the attached one and the error you described will not be reproducible.   Let me know if you have any questions.