Stop LINQ to SQL dbml from updating connection string when I drag tables into the dbml file

Every time I drag a modified table into my dbml, VS2010 wants me to update the connection string even though I have created a data connection with the exact same information. Every time this happens it changes my connection string to 'DataSourceConnectionString' and I have to delete it from 5 different files and replace it with the name of the connection string I was using previously so it doesn't screw up everyone else using the file through source control. Any Ideas?