We recently ran into a problem installing the Enterprise 5.1 SageSalesLogixMobile database on a sql database server with SQL Server 2005.  The Sage Platform manager would complete successfully and the connector would install but not connect.  As a verification the Sage Mobile Connector service was checked and it indeed was not running nor could it be started manually.  After a little searching we concluded the "enforce password policy" option was creating a password that was incompatible with the internal encrypted password and we could not login to the db through Management Studio.   Our eventual solution was to delete the existing database and SageMobile user logging and recreate the database without enforcing password policy for the new db.