Problem dependecies with refrence SqlServerCe.dll (With new element)

I have VB 2008 (not SP1).
I have reinstalles this one recently, and I have problems !
When developping for Smartphone, I have an error while trying to create a
dataset (by "Project/Add a module/Dataset") : error of personnalised
(outil) : Generation of code failed. Reference of an object is not defined
as an instance of an object (exactly in french : "Erreur de l'outil
personnalisé : Echec de la génération du code. La référence d'un objet n'est
pas définie à une instance d'un objet")
Second :
I have a problem of dependencies with SqlServerCE.dll.
All dependencies of all my references are on, except
System.Data.SqlServerCe.dll, whose dependencies are Mscorlib,
System, and System.Data
Not only in ancient program, but on new program too.

I create a program like this :
New Project. I choose "Smar device project", then "Smart device application"
with "Windows Mobile Professional SDK" and ".net Compact Framework Version
VS 2008 create a form1.
I add a refrence to "".
I save project and I add a new Project to the solution (Project CAB smart
In this new project, VS2008 add refrences after adding to Application
directory the principal output of my project. If I look at alll the
dependenciesof the references automatically added by "project CAB smart
device" I see :
- microsoft.visualbasic.dll
- microsoft.WindowsCE.forms.dll
- mrcorlib.dll
- System.code.dll
- System.dll
- System.drawing.dll
- System.wml.dll
- System.Xml.linq.dll
All dependencies of all refrences are, except, whose referencies are

So I have error. I can launch my program, but I can not generate it, because
"MSB3247 : Des conflits entre différentes versions du même assembly
dépendant ont été rencontrés. SmartDeviceProject2" (conflicts betweeen
different versions of same dependent assembly)

How can I repair these errors met after a reinstallation of VS2008 ?

When I try to create a new Compact server database .sdf, I cannot do that,
because I have not the choice of create a .sdf file, but only a .mdf file.

In "Add/remeve programs" I have these installations :
- Microsoft .NET Compact framework 2.0 SP2
- Microsoft .NET Compact Framework 3.5
- Microsoft .NET Framework 2.0 Service Pack 2
- Microsoft .NET Framework 2.0 Service Pack 2 Language pack - Fra
- Microsoft .NET Framework 3.0 Service Pack 2
- Microsoft .NET Framework 3.0 Service Pack 2 Language pack - Fra
- Microsoft .NET Framework 3.5 SP1
- Microsoft SQL Server 2005
- Microsoft SQL Server 2005 Compact 3.5 for devices FRA
- Microsoft SQL Server 2005 Compact 3.5 FRA

Thanks very much for your help, and excuses for my english language !.