Topic: AJAX request is not populating data all the time

I have two combo box. One is life of business and one is claim types. Each line of business has associated list of claim type.

On changing 'line of business' its populating respective 'claim types'.
Code for that is as mentioned below.

<%= observe_field 'claim_line_of_business_id',
        :url => {:action => :get_claim_types_by_line_of_business },
        :with => "line_of_business_id" %>

this will call my get_claim_types_by_line_of_business which will get the data for claim types for respective line of business.

Code of get_claim_types_by_line_of_business.rjs is as written below.

if params[:claim_office_id]
  @consultants_in_office = Consultant.find(:all, :conditions => ['office_id = ? AND role_id = ?', params[:claim_office_id], Role.find_by_title('Consultant')])
  page.replace "claim_consultant_id", :partial => 'consultants_in_office'
else
  page.replace "claim_consultant_id", :partial => 'blank_consultant'
end

Its working fine for 90% but some time its not populating the field. Its also working fine in firefox without any problem

Thanks in advane

Atit