One possible source of error is that you don't define the column names when inserting the data. If the columns are in different order you could end up inserting but in the wrong columns. In this kind of case you wouldn't find newly inserted rows.
Try changing the insert into
insert into A_PFMonitoring_Users (usercode, userpass) values(@docID, @pass)
Also since you're updating only one table, you can simplify the update by removing the aliases. For example
update A_PFMonitoring_Users set userpass=@pass where usercode=@docID