Dropdown list changed event not firing in sharepoint site

Dear all,

I am facing a problem not getting any solution after googling. The problem is dropdown changed event is not firing after publish to the sharepoint site. But in infopath 2010 form preview it works perfectly, I set property like the fully trusted form, always postback. 

In my form there three fields

 1)DDLFirst,

2)txtFirst,

 3)DDLSecond(repeating table)

Data connection is webservice data connection, at first step using SOAP data connection I am filling the First Dropdownlist. Then using infopath rules,  action  and filter,  based on First Dropdownlist selection filling the textboxFirst control. And based on value coming the textbox populating the secondDropdownlist(in repeating table).

 

Its perfectly working fine in preview mode but after publishing to the sharepoint 2010 site the dropdown changed event is not at all firing.

 

How I published the form below are the steps:

After entering the site URL, in publishing Wizard I am selecting the below two option

a)      Enable this form to be filled out by using a web browser.

b)      Administrator approved form type.

 

After publishing the form I went to the sharepoint central admin from there I am uploading the recently published inform. After uploading I am clicking on the verify button , there I am getting an warning message:

 

"The Filter expression is on external data and could not be validated. It may not be supported in web browser forms."

 

 

After analyzing for long time I confirmed above message is the root cause for not firing the dropdown list changed event after publishing.

 

Any help would be highly appreciated and like me many google hunter will be helped. How to fix the above highlighted warning message.