problem with ScrewTurn Wiki

I just installed WIKI 2.0.36 on my (DiscountASP.Net) shared host, most seems to work until I try to create a new user account, I get
"We're sorry, an error occurred while processing your request"

Log shows :

<!-- m -->http://www.quantum-limited.com/Wiki/Register.aspx<!-- m -->
System.Web thrown System.Web.HttpException
The type 'System.Web.UI.ScriptManager' is ambiguous: it could come from assembly 'C:\WINDOWS\assembly\GAC_MSIL\System.Web.Extensions\3.5.0.0__31bf3856ad364e35\System.Web.Extensions.dll' or from assembly 'C:\WINDOWS\assembly\GAC_MSIL\System.Web.Extensions\1.0.61025.0__31bf3856ad364e35\System.Web.Extensions.dll'. Please specify the assembly explicitly in the type name.
at System.Web.Compilation.CompilationUtil.GetTypeFromAssemblies(AssemblyCollection assembliesCollection, String typeName, Boolean ignoreCase)

Ideas ?

Later,
Paul

 

OK, I know what is causing my problem.
I have the Wiki's web.config in a /Wiki/ subdirectory, but I also have a web.config in the root directory for
the main website.
The 2 config files conflict, breaking the Wiki.
Any ideas on how to solve this ?
Later,
Paul