No data found using XI, but found using Test Function Module !!

Hi,

I am using SOAP-XI-RFC scenario.

I can successfully get data into my application for some XXX entity.

But, for YYY entity I am not getting data using XI.

I receive a blank XML Response from XI,

When I see the data using the same BAPI_XX I used in XI, it returns me some data in CRM 4.0 !!

What can be the possible causes for it!

Thanks,

Narendra.