Sync creating multiple subscription sqlcereplication

I am currently developing a bridge between a database and a sql server database android (sqlite).

To do this, I use a web service and filtered replications with sqlce databases stored on a server IIS 7. To develop this, I used IIS Express on my pc. Everything works fine on my pc but when deployed, replicated databases create a new subscription for each synchronization (while on IIS Express sync works without creating a new subscription), no exceptions are thrown, nothing.

I don't understand why IIS 7 or IIS Express works in a different way to sync databases.

An idea of ​​the reason of the problem?

I use Sql replication ce 3.5 sp2, Sql server 2008 R2 as mother database, IIS7.

I tried to : -Replicate motherdatabase with a little software on the webserver, it works. -Use "SqlCeReplication.loadproperties" to find my sqlce database parameters to avoid the creation of the new subscription, it doesn't work.

Other details : -When it is not syncing for the first time, webservices don't do "repl.AddSubscription(AddOption.CreateDatabase)", I already check that.

Here is the code used to sync :

' Define the server, publication, and database names.
Dim repl As SqlCeReplication = Nothing
Try
    repl = New SqlCeReplication
    repl.Publisher = PublisherName
    repl.PublisherLogin = login
    repl.PublisherPassword = password
    repl.PublisherSecurityMode = SecurityType.DBAuthentication
    repl.PublisherDatabase = My.Settings.DBName
    repl.Publication = PublicationName
    repl.InternetUrl = "https://iis.mydomain.com:444/sql/sqlcesa35.dll"
    repl.InternetLogin = "sync"
    repl.InternetPassword = "dfssd"
    repl.Subscriber = "MobileApp - " & login
    repl.SubscriberConnectionString = "Data Source=" & My.Settings.folderDB + "\" + subscriptionName + ".sdf"
    If Not File.Exists(My.Settings.dossierBDD + "\" + subscriptionName + ".sdf") Then
        repl.AddSubscription(AddOption.CreateDatabase)
    End If
    repl.Synchronize()
Catch err As SqlCeException
Finally
    repl.Dispose()
    repl = Nothing
End Try

Thanks in advance