Do you know what is the purpose of the following line in the "body" section of the Site.Mater in the asp:ScrptManager:
<asp:ScriptReference Name="jquery" />
If I remove this line the Mask works. Once I put it back, it does not.
UPDATE. It is not consistent. I need to get away from this problem; for the time being or for good.
"The creative process is nothing but a series of crises." Isaac Bashevis Singer
"My experience is that as soon as people are old enough to know better, they don't know anything at all." Oscar Wilde
"If a nation values anything more than freedom, it will lose its freedom; and the irony of it is that if it is comfort or money that it values more, it will lose that too." W.Somerset Maugham