Hello Virgul,
I'm not sure if i fully understood the issue so let me put it my own words and you can correct me if i have it wrong.
You have a data connection to a Webservice. This is a Recieve data connection and you get data from the Web service that you now want to use to populate a dropdown in the UI?
To do this in the Dropdown properties you need to select the third option "Look up values in a data connection to a database ....", choose the appropriate data conection and then map the Entries, Value and Display ame to the data that you want to see in the dropdown.
Hope this helps!
Shanthi
InfoPathDev India
Shanthi Reddy