Error installing Navision Smart Tag Integration Web Service

Hello,
I'm trying to install the web service to use smart tags. At the end of the install (which finished correctly), the TestWS.exe tests my installation and fails because of a problem that is written in TestWS.log. The problem is the WebCaching, but I don't know what the webcaching is...

Can someone help me ?

Here is the .log content, it's in French but understandable by everyone I hope...

[FileNotFoundException]: Le fichier ou l'assembly nommé WebCaching ou l'une de ses dépendances, est introuvable.
at Navision.SmartTags.Global..ctor()
at ASP.Global_asax..ctor() in c:\WINDOWS\Microsoft.NET\Framework\v1.1.4322\Temporary ASP.NET Files\smarttags\337e3785\65e2ddc7\t9xgxlh0.0.cs:line 32
[TargetInvocationException]: Une exception a été levée par la cible d'un appel.
at System.RuntimeType.CreateInstanceImpl(Boolean publicOnly)
at System.Activator.CreateInstance(Type type, Boolean nonPublic)
at System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
at System.Activator.CreateInstance(Type type, BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
at System.Web.HttpApplicationFactory.GetSpecialApplicationInstance()
at System.Web.HttpApplicationFactory.FireApplicationOnStart(HttpContext context)
at System.Web.HttpApplicationFactory.Init(HttpContext context)
at System.Web.HttpApplicationFactory.GetApplicationInstance(HttpContext context)
at System.Web.HttpRuntime.ProcessRequestInternal(HttpWorkerRequest wr)