In AppStudio, when I connect to my web service I get not only the fields within the methods but also fieldnameSpecified fields as well.
Your web service contains Nullable primitives. A Nullable primitive (coded in .NET as "Bool?" or "Int?") is a variable that could have a value or be null. For example, a regular integer can be any whole number, but a nullable integer can be any whole number as well as null.
When a nullable primitive is used, this field is created by the Net Service Reference. Further discussion can be found here: http://stackoverflow.com/questions/1128403/different-behavior-between-service-reference-and-web-reference