....Popup' null or not an object t:popup not working

[bs]

Hi,

Iam trying to use t:popup in h:dataTable
iam getting an  error
....Popup' null or not an object
sometimes i get
orgApacheMyFacesPopup not defined

all my web.xml files are updated for 1.1.3 (myfaces,tomahawk)
do you know what is happening?

thank you