• thank you for input Smendle.

    I have found the issue - now all I need is time....it's a complicated suite of packages designed by a third party

    The reason for the failures was not the installation but rather the nature of the DTS. The packages I am running are nested - so the first package calls another package as its second step; the second package then runs another few packages in turn before returning control to the first package which then runs another and so on. That worked fine on SQL Server 2000 and SQL Server 2005. When I run any of the packages individually they run but the nests do not.

    I found the answer here thanks to Salekin Khan:

    https://social.msdn.microsoft.com/Forums/sqlserver/en-US/e192f6bb-471e-4193-b9cf-5bfefcde3158/how-to-schedule-legacy-dts-package-in-sql-server-2008?forum=sqlintegrationservices

    and it said:

    .....When you create a SQL Server Agent job to run packages, you must create a separate step for each package that you want to run