This is a question asked by a friend of mine in microsoft.public.vsnet.enterprise.tools forum. I'm facing the same issue. But may be that was a wrong forum to ask, so I'm posting the same question here, of course with his permission. Please help us with your ideas and thoughts. Thank you all.

The link to the original post - http://groups.google.com/group/microsoft.public.vsnet.enterprise.tools/msg/ba8802845c217224

I'm using the Enterprise Library Configuration tool to manage the
Enterprise Library parts of my Web.config.

I'm also using the
System.Web.Security.ActiveDirectoryMembershipProvider, and I have to
supply it with the name of a connection string defined in
<connectionStrings>. The connection string looks like this:

<add name="AD" connectionString="LDAP://domain.my" />

When ELC saves the .config file, it doesn't recognize this type of
connection string (there's no data source, no provider name etc) so it
justs blanks it, changing it to:

<add name="AD" connectionString="" />

What is the solution to this?

(The only workaround I can think of is setting the membership
provider's connection string at runtime, but I don't know if that's
possible.)