Thanks for the reply, Wayne. We installed the ACE drivers when they were first published and are using them sucessfully. It was necessary to do so in order to be able to use the Access source in the original package. (JET limited us to MDB, and this source was ACCDB.)

The connection strings in the original package and the new package in question are both as follows:

Data Source=\\filesrv\publishing\DPS Plays Database\DPS Plays.accdb;Provider=Microsoft.ACE.OLEDB.12.0;

As I noted above, the new package runs fine in both VS and MSDB. It is only the SQL Job that causes it to fail. But why?