If your Calendar Extender doesn’t render properly, normally because its’ style has been overriden by the css. As Calendar heavily use DIV, TABLE. To recover this just wrap your textbox and calendar in <DIV class=”calendarContainer “>
and put the following lines in your css:
.calendarContainer table tr td
And check your css file doesn’t include
it will set haslayout = true, and you have no way to set to false later.
Look http://www.satzansatz.de/cssd/onhavinglayout.html for more details