Migration Error from Vault 2009 to Vault 2011

A partner kindly shared this solution with us today when they encountered this migration error found in the ADMS Console Log.

23/03/2011 13:18:23 Migrating "<vaultname>" database... 0/7
23/03/2011 13:20:24 ScriptMigrationOperation: Connectivity.Core.Database.Sql.Migration.CoreVault_9.0.5_to_9.0.6.sql
23/03/2011 13:37:03 Connectivity.Application.VaultManager.ServiceException: The CREATE UNIQUE INDEX statement terminated because a duplicate key was found for the object name 'dbo.ContentSourceProperties' and the index name 'PK_ContentSourceProperties'. The duplicate key value is (7, IMG.SRC!{C82BF597-B831-11D0-B733-00AA00A1EBD2}!ntext, 168917).
Could not create constraint. See previous errors.
The statement has been terminated. ---> System.Data.SqlClient.SqlException: The CREATE UNIQUE INDEX statement terminated because a duplicate key was found for the object name 'dbo.ContentSourceProperties' and the index name 'PK_ContentSourceProperties'. The duplicate key value is (7, IMG.SRC!{C82BF597-B831-11D0-B733-00AA00A1EBD2}!ntext, 168917).
Could not create constraint. See previous errors.

The statement has been terminated.
at Connectivity.Core.Database.TransactionContext.OnSqlException(SqlException e)
at Connectivity.Core.Database.SqlAccess.e(SqlCommand A_0)
at Connectivity.Core.Database.SqlAccess.ExecuteNonQuery(CommandType commandType, String[] commandText, Int32 commandTimeout, SqlParameter[] commandParameters)
at Connectivity.Core.Database.SQLScript.a(a A_0, String[] A_1, Int32 A_2, SqlParameter[] A_3)
at Connectivity.Core.Database.SQLScript.a(String A_0, Int32 A_1, SqlParameter[] A_2)
at Connectivity.Core.Database.SQLScript.ExecuteScript(Assembly asm, String resourceName, Int32 commandTimeout, SqlParameter[] parameters)
at Connectivity.Core.DataAccess.ScriptMigrationOperation.ExecuteMigrationScript(String assemblyName, String resourceName)
at Connectivity.Core.DataAccess.ScriptMigrationOperation.Execute()
at Connectivity.Core.Operations.Migrate.a(Migration A_0)
at Connectivity.Core.Operations.Migrate.Execute()
at Connectivity.Core.Operations.MigrateVault.Execute()
at Connectivity.Core.Services.KnowledgeVaultService.MigrateKnowledgeVault(String vaultName, OnProgressDelegate onProgress)
at System.Runtime.Remoting.Messaging.StackBuilderSink._PrivateProcessMessage(IntPtr md, Object[] args, Object server, Int32 methodPtr, Boolean fExecuteInContext, Object[]& outArgs)
at System.Runtime.Remoting.Messaging.StackBuilderSink.PrivateProcessMessage(RuntimeMethodHandle md, Object[] args, Object server, Int32 methodPtr, Boolean fExecuteInContext, Object[]& outArgs)
at System.Runtime.Remoting.Messaging.StackBuilderSink.SyncProcessMessage(IMessage msg, Int32 methodPtr, Boolean fExecuteInContext)
--- End of inner exception stack trace ---
at Connectivity.Application.VaultManager.ProgressCommand.Execute()
at Connectivity.Application.VaultManager.MigrateAllCommand.a(LoginInfo A_0)
23/03/2011 13:37:03 Migration of '<vaultname>' failed: The CREATE UNIQUE INDEX statement terminated because a duplicate key was found for the object name 'dbo.ContentSourceProperties' and the index name 'PK_ContentSourceProperties'. The duplicate key value is (7, IMG.SRC!{C82BF597-B831-11D0-B733-00AA00A1EBD2}!ntext, 168917).
Could not create constraint. See previous errors.
The statement has been terminated.

The solution here was to install Vault server 2011 Update 2 then migrate