sorry typo - should be mdf - SQL database.
The statement you quoted was what I understant to be the requirements for ASP.NET membership login to work. I have been it contact with someone who has created a turorial on setting up the login process.
This is my full web.config file (I should add that I have tried various permutations e.g. datasource with & without the localhost)
<?xml version="1.0"?>
<configuration xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0">
<connectionStrings/>
<remove name="LocalSqlServer"></remove>
<add name="LocalSqlServer"
connectionString="Data Source=87.117.201.122/localhost;
User ID=gav23;
Password=qw34;
Initial Catalog=ASPNETDB_Data;"
providerName="System.Data.SqlClient" />
</connectionStrings>
<system.web>
<authorization>
<deny users="?" />
</authorization>
<authentication mode="Forms" />
</system.web>
</configuration>