My problem may be the same as issue 87851000000853007 http://help.creator.zoho.com/Issues-List.html

I have three lookups on form A looking up information from form B. When I add criteria to the Lookup and click Done the field disappears from the form. It reappears when I refresh the screen but the criteria is not saved. 

I was able to get this to work by coding directly in the Form Definition.

Herb Wexler