“SQL Server does not exist or access denied.”

Have resolved the problem, the Port was different and so the Connection String now reads:

<connectionStrings> 
<add name="IWSR_DataDownloadWizard.My.MySettings.sqlConnection" 
    connectionString="Provider=SQLOLEDB.1;Data Source=SQLServer,2433;Integrated Security=SSPI;Initial Catalog=IWSROL" 
    providerName="System.Data.OleDb" /> 

(not the new port number after the DataSource name).

Just WHY it works on my machine and not in deployment though I really have no idea